This study reports the green synthesis of Yttria-Zinc Oxide Y2O3 - ZnO) (YOZ) nanohybrids using Caulerpa lentillifera extract as a green stabilizer and evaluates the effect of pH variation (9.0, 10.0, 11.0) on their physicochemical and biomedical properties. Sol-gel-hydrothermal synthesis followed by calcination at 600 degrees C produced YOZ nanohybrids (YOZ-9, YOZ-10, YOZ-11), with ZnO and Y2O3 used as comparative controls. The XRD patterns of YOZ confirmed the coexistence of hexagonal wurtzite ZnO and cubic Y2O3, with emphasis on the dominant (101) plane, which exhibited the highest crystallinity intensity. The crystallite size ranged from 41.8 to 48.1 nm. Meanwhile, the FTIR spectra revealed Zn-O-Y vibrations (400-600 cm(-1) ), supported by biomolecular residues that indicated successful hybridization. Thermal analysis showed improved stability up to similar to 850 degrees C, and UV-Vis DRS demonstrated a narrowed bandgap (3.09-3.07 eV) compared with ZnO (3.17 eV). The SEM images showed distinct morphologies at each pH, with highly uniform nanorods observed at YOZ-11. YOZ-11 exhibited the highest antibacterial activity against Staphylococcus aureus (25 mm, MIC: 184.09 mu g/mL) and Candida albicans (23 mm, MIC: 159.66 mu g/mL). Each of the other biomedical parameters also showed stronger indications than the positive controls, including along with strong of antioxidant activity (IC50 = 43.77 rho g/mL), anti-inflammatory activity (59.78 mu g/L), antidiabetic activity (429.90 mu g/mL). These findings highlight the Caulerpa lentillifera based YOZ nanohybrids as stable, eco-friendly, and multifunctional materials showing promising photoresponsive multifunctional biomedical activity under controlled irradiation conditions.

This study investigates the eco-friendly synthesis of TiO2 NPs using Melastoma malabathricum fruit extract and lime juice as natural reducing and capping agents. The extract was prepared by macerating the sample in ethanol. TiO2 NPs were synthesized via the sol-gel method with five variations: one control sample using ethanol only and four samples incorporating plant extracts with varying lime juice concentrations. The results confirmed the formation of pure anatase-phase TiO2 with crystallite sizes decreasing from 18.17 to 12.43 nm. Optical analysis revealed bandgap energies of 3.09-3.14 eV, suitable for dye-sensitized solar cell (DSSC) applications. The field-emission scanning electron microscopy (FESEM) images revealed more uniform, smaller particles in the capped samples, as supported by the particle-size distribution data. energy-dispersive X-ray spectroscopy (EDX) confirmed that the elemental composition is close to stoichiometric TiO2. Electrochemical analysis indicated that the sam(power conversion efficiency (PCE) = 3.12%) owing to enhanced charge injection, despite a extract and lime juice exhibited improved charge retention (tau e = 205-274 ms), despite their moderate efficiencies (2.26-2.49%). This study demonstrates the significant potential of tropical performance governed by careful optimization of the composition of natural capping agents.

The macroalga Sargassum siliquosum contains amino-cellulose bioactive compounds that act as stabilizing agents and growth controllers for metal precursor ions in the synthesis of Mg-Y/ZnO nanorods. This study aims to improve the multifunctional biomedical performance of ZnO (antibacterial, antioxidant, anti-inflammatory, and antidiabetic) through bimetal ion doping using Magnesium (Mg2+, 0.71 Å) and Yttrium (Y3+, 1.05 Å) at concentration ratios of 0.01–0.03 M within the ZnO lattice. Thermal analysis (TGA/DTA) shows that Mg-Y doping reduces the thermal stabilization temperature of ZnO from 800°C to 600°C. X-ray diffraction confirms the formation of a hexagonal wurtzite structure without secondary phases, supported by Rietveld refinement, FT-IR bonding profiles, and UV-Vis (Tauc plot) band gap narrowing to 3.01–3.10 eV. FE-SEM images reveal nanorod morphology of 25–35 µm, while EDX verifies Mg and Y incorporation. The doped samples exhibit strong antibacterial activity, with inhibition zones of ≥ 20 mm against Staphylococcus aureus and Pseudomonas aeruginosa. The 0.03 M Mg-Y/ZnO sample exhibits the highest biomedical performance, with significant antioxidant (IC₅₀ = 71.6 mg/L), anti-inflammatory (368 mg/L), and antidiabetic (420 mg/L) activities. These results indicate that Mg-Y bimetal doping enhances ZnO functionality and offers promising potential as a multifunctional biomedical material.

The 2025 Nobel Prize in Physics 2025 delivered a message with immediate relevance for engineers: quantum behavior can be realized in engineered circuits. John Clarke, Michel H. Devoret, and John M. Martinis “for the discovery of macroscopic quantum mechanical tunneling and energy quantization in an electric circuit.” This recognition is not only a milestone in fundamental physics but also a clear signal that quantum phenomena can be approached through design choices, fabrication routes, measurement strategy, and system integration—the everyday language of engineering research. For an engineering community, the significance is not simply what was discovered but how it reframes participation. Once a circuit exhibits tunneling and discrete energy levels, quantum science becomes more than a theoretical construct: it becomes something that can be specified, tested, and iteratively improved. The frontier that opens here is not a claim that quantum systems are “solved,” but that they are increasingly engineerable, and therefore, reachable when physics is translated into performance metrics, process discipline, and reliability thinking.Where engineers enter the quantum field Quantum circuits operate in the microwave regime, and their performance critically depends on the resonator design, coupling, impedance environment, filtering, shielding, and amplification. In practice, the “quantum” part is inseparable from radio frequency (RF) engineering decisions that shape readout fidelity and stability (Kurniawati et al. 2023, Rahayu et al. 2021, Sholeh et al. 2020). Materials science and surface/interface engineering Practical device limits are often traced to surfaces, interfaces, thin films, and microscopic defects. This places deposition, cleaning, passivation, metrology, and microstructural control at the center of progress. This is mostly because improved material quality can translate into improved coherence and consistency [Udhiarto et al., 2014; Whulanza et al., 2015; Suwandi et al., 2014]. Micro/nanofabrication and manufacturing quality. Once quantum systems become circuits, they inherit manufacturing realities: process windows, run-to-run variation, wafer-level screening, and yield learning. Therefore, quantum engineering requires the same discipline used in advanced manufacturing, such as statistical process control, failure analysis, and design-for-manufacture. (Whulanza, 2015; Suwandi, 2019; Rahman et al., 2025). Cryogenics, instrumentation, and metrology Experiments requiring extreme environmental control and precision measurement The transcript’s emphasis on instrumentation as a pathway to quantum insight reflects a key point: cryogenic integration, packaging, calibration, and low-noise measurement are not peripheral. They often determine what phenomena can be observed and what performance can be validated [2023]. Hernandez et al., 2023]. Control, computer engineering, and software-defined (SD) experimentation. The operation of quantum hardware requires layered control stacks: waveform generation, timing synchronization, feedback, calibration routines, and automation. As noted in the transcript, this work sits near the “bottom” of a computing stack. However, the system value depends on how engineers integrate diagnostics, control, and reliability practices into repeatable workflows [Nugroho et al., 2023; Siregar, 2025; Nugroho, 2023]. Reliability, noise engineering, and system integration The “enemy” of engineered quantum behavior is electromagnetic, thermal, material, and even packaging-related noise. Noise modeling, root-cause analysis, and reliability frameworks are as important as physics derivations. Scaling also introduces the following system-level questions: interconnects, shielding, crosstalk, modularity, maintainability, and qualification protocols (Aprilia et al., 2024; Chaicayet et al., 2025; Putri et al., 2025). For the IJTech community, this is an invitation to contribute with methods already familiar in other technology domains, such as materials optimization, process development, design-for-manufacture, reliability engineering, and system integration. Therefore, the emerging identity of “quantum engineering” is not an add-on to physics; it is a convergent space where multiple disciplines can drive measurable progress.

This work aims to explore the characteristics of TiO2 NPs green-synthesized via an environmentally friendly method using oil palm (Elaeis guineensis) leaf extract as a green medium and capping agent by utilizing titanium tetra isopropoxide (TTIP) as precursor. The oil palm leaves were extracted with different solvent concentration variations. The natural extract was characterized using liquid chromatography-mass spectroscopy (LC-MS) and infrared spectroscopy for active chemical contents and functional groups. The obtained TiO2 NPs were also characterized using infrared spectroscopy (FTIR) for the functional groups, ultraviolet spectroscopy (UV-DRS) for the optical characteristics, and X-ray diffraction (XRD) for the phase formation and crystallographic properties. More sophisticated equipment of field emission scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (FESEM/EDX) and Raman spectroscopy were employed to reveal the characteristics of the obtained TiO2 NPs. The results from X-ray diffraction showed that the obtained TiO2 NPs are in pure anatase crystal structure. There is also a trend that the bandgap energy of TiO2 NPs reduces with the use of oil palm leaves extract as a green medium. It is confirmed that the green medium affects the optical characteristics of the synthesized TiO2 NPs by reducing the bandgap energy from 3.2 eV for commercial and the one synthesized using ethanol only to 3.12 eV by using the green medium of oil palm leaves extract. These findings will provide insight for more novel, environmentally friendly nanomaterials synthesis methods.

The limited availability of biocompatible metal oxide photocatalysts that are responsive to visible light remains a major challenge in the development of environmentally friendly biomedical materials, as most conventional photocatalysts are active only under ultraviolet (UV) irradiation, which exhibits low tissue penetration. The functional performance of metal oxide nanohybrids can be tailored through heterojunction formation via green synthesis strategies to control morphology, crystal structure, optical properties, and biological activity under visible-light irradiation. In this study, ZnO-MgO-CuO oxide nanohybrids were synthesized using a green synthesis approach employing amino cellulose extracted from the red macroalga Gelidium pusillum as a natural reducing and stabilizing agent. Two molar ratio compositions were prepared (Zn:Mg:Cu = 1:1:1) which consist of (0.1 M: 0.1 M: 0.1 M) and (0.2 M: 0.2 M: 0.2 M) to evaluate the effect of precursor concentration on structural evolution, band gap modulation, and biomedical performance, with single oxides (ZnO, MgO, and CuO) used as reference materials. XRD, FTIR, TGA-DTA, SEM-EDX, and UV-Vis-DRS analyses confirmed the formation of a mixed-phase crystal structure (hexagonal-cubic-monoclinic) after calcination at 850 degrees C, with rod-like, cubic, and spherical morphologies (similar to 70 nm) and visible light responsive band gap energies in the range of 2.62-2.82 eV. Biological evaluations revealed that ZMC-2 exhibited the highest antioxidant activity (58.2%; IC50 = 46.3 +/- 0.01 mu g/mL. Antibacterial activity under visible-light irradiation against Staphylococcus epidermidis and Salmonella typhosa demonstrated inhibition zones up to 35 +/- 0.04 mm. These findings highlight the potential of green synthesized ZnO-MgO-CuO nanohybrids as multifunctional materials for biomedical-oriented applications.

This work aims to examine the properties of titanium dioxide nanoparticles (TiO2 NPs) synthesized through a sustainable, chelating-assisted green process using mangosteen (Garcinia mangostana L.) pericarp extracts for use as a semiconductor layer in dye-sensitized solar cells (DSSCs). X-ray diffraction (XRD) characterization revealed that the TiO2 NPs have a tetragonal crystalline structure and are pure anatase. The optical characteristics examined using ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) showed a reduced bandgap energy, from 3.22 to 3.20 eV, with the use of mangosteen pericarp extract. The same trend is observed with the use of chelating agent concentration, decreasing from 3.20 to 3.10 eV at 30%, then increasing slightly to 3.14 eV at 50%. The TiO2 NPs were further used as a semiconductor layer in a DSSC device sensitized with the commercial dye N719 and a natural dye derived from Malabar spinach (Basella rubra L.) fruit extract. The highest efficiency of 2.34% was achieved with a DSSC device fabricated from green-synthesized TiO2 NPs using mangosteen pericarp extracted with 50% acetylacetone (AcAc) and sensitized with N719, slightly lower than that of commercial TiO2 P25 (2.65%). The efficiencies of the same materials sensitized with natural dyes from Malabar spinach fruit extract are 0.69% and 1.01%, respectively. These results demonstrate the potential of using mangosteen pericarp waste and natural dyes for the sustainable, cost-effective fabrication of DSSCs.

The growing need for cost-effective and scalable photovoltaic technologies has intensified research on platinum-free (Pt-free) counter electrodes (CEs) for dye-sensitized solar cells (DSSCs). This review examines recent developments across major classes of alternative CE materials, including carbon-based structures, transition-metal sulfides, oxides and nitrides, conductive polymers, metal selenides, and low-cost metals and metal alloys such as Ni, Cu, Ti, and their compounds. The analysis highlights how morphology engineering, heterostructure design, and synergistic material integration improve catalytic activity toward the I₂/I₃⁻ redox couple, electrical conductivity, and long-term stability. Comparative evaluation shows that several Pt-free systems, such as RuS₂/rGO/MWCNTs, Ni- and Co-based sulfides, and selected metal alloy composites, achieve power conversion efficiencies comparable to or exceeding those of Pt-based electrodes, with reported values exceeding 13 % in optimized configurations. Emerging synthesis strategies, including hydrothermal growth, electrochemical deposition, and fabrication of nanostructured composites, further enable high-performance, scalable electrode architectures. Overall, the review identifies key trends driving the advancement of Pt-free CEs and discusses remaining challenges related to electrolyte compatibility, durability, and industrial-scale fabrication, thereby providing a foundation for the future development of sustainable and economically viable DSSC technologies.

Tin oxide (SnO2 ) as a wide bandgap semiconductor shows promising photocatalytic properties; however, commercially available precursors, which are costly, are often used to develop its nanomaterial. With its abundant natural resources, Indonesia has the potential to replace these commercial precursors with locally sourced alternatives. This study explores the synthesis of SnO2 using a local tin chloride (SnCl4) and investigates its photo catalytic performance through methylene blue degradation. The SnO2 samples were synthesized using the hydrothermal process at 180 degrees C for 24 h. Furthermore, to optimize the process, the pH of the solution was also tuned at 1, 7, and 11 to analyze its effect on material properties. Characterization techniques, including X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, UV-Vis spectroscopy, particle size analyzer, zeta potential, and N2 adsorption-desorption analysis, were used to evaluate the structural, morphological, and optical properties of the synthesized materials. The samples synthesized in all pH conditions after the hydrothermal process were confirmed to be tetragonal rutile SnO2 . Additionally, the crystallite size, optical properties, and morphology of the samples are affected by different pH conditions. SnO2 synthesized at pH 11 has a high BET surface area of 132.12 m(2)/g and mesoporous properties. The photo catalytic performance of the synthesized SnO2 achieved a degradation of methylene blue over 95% using UV irradiation for 120 min. The high degradation of dye can be attributed to the adsorption capability exhibited by the high surface area of the synthesized sample. This study proves that SnO2 synthesized using locally sourced SnCl4 shows comparable photo catalytic performance to commercial materials.

Growing global freshwater scarcity has intensified demand for efficient seawater desalination technologies, yet conventional cellulose acetate (CA) membranes remain limited by insufficient hydrophilicity and suboptimal salt rejection performance. In this study, CA was combined with graphene oxide (GO) to produce CA/GO composite membranes, and their salt rejection performance in a seawater loose nanofiltration system was reported. These membranes were synthesized via phase inversion by varying GO concentration to be 0.5, 1.0, and 1.5 wt% into CA polymer as matrices at 15 and 25 wt%. The structural, chemical, and morphological properties of raw materials and the membranes were characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field-emission scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (FESEM-EDX), and water contact angle measurements. The results showed that the CA 15 wt%/GO 1 wt% membrane demonstrated the most favorable balance of performance, achieving a water flux of 11.80 L/m²·h and the highest salt rejection of 37.75%, corresponding to a permeate TDS of 23,033 mg/L, alongside the lowest water contact angle of 74.12° among equivalent CA-concentration membranes, indicating enhanced hydrophilicity. The XRD analysis confirmed increased crystallinity (up to 58.08%) with introduction of GO while the FESEM revealed a uniform GO dispersion within the CA polymer matrix. These findings demonstrate that controlled GO incorporation into CA membranes significantly enhances membrane hydrophilicity and salt rejection efficiency, establishing CA/GO composites as a viable and scalable platform for seawater loose nanofiltration applications as pre-treatment.

Silicon nanoparticles (SiNPs) can be synthesized by the hydrothermal method. This study synthesized silicon nanoparticles from rice husk ash using the hydrothermal method with ratios SiO2:Mg of 1:1.5, 1:2, and 1:2.5. A ratio of SiO2:Mg of 1:2.5 (SiNPs2.5) is the optimum for SiNPs synthesized, with a surface area and pore size of 41.69 m2/g and 8.28 nm, respectively. SiNPs2.5 was applied to a lithium-ion battery, yielding a capacity of 2101 mAh/g.

The synthesis of titanium dioxide (TiO₂) nanotubes from natural ilmenite minerals has garnered significant research interest due to its abundance and low cost. This study explores a controlled process to transform ilmenite into TiO₂ nanotubes, leveraging its inherent properties. Ilmenite was processed via hydrometallurgy technique using the sulfate route after mechanical activation. The resulting leachate solution containing TiOSO₄ was further hydrolized to form TiO₂ nanoparticles which were subsequently converted into nanotubes through hydrothermal treatment at 150°C in 10 M NaOH for 24 h. The as-synthesized product, displayed tubular morphology, with inner and outer diameters of 3.75 ± 0.61 nm and 9.35 ± 1.50 nm, respectively, and a length ranging from 30 to 120 nm, and a high specific surface area of 256.81 m²/g, classifying it as mesoporous. The optical study revealed a band gap energy of 2.80 eV, influenced by natural iron doping (0.94 wt%), while photoluminescence analysis indicated a reduced electron-hole recombination rate. Photocatalytic performance, assessed through methylene blue (MB) degradation, achieved up to 98 % removal under combined dark and visible light conditions within 120 min. The improved adsorption is attributed to the material’s tubular structure and high surface area, while photocatalytic enhancement is primarily influenced by the narrowed bandgap and suppressed electron–hole recombination. These findings underscore the synergistic contribution of adsorption and photocatalysis in organic pollutant degradation and highlight the potential of ilmenite-derived TiO₂ nanotubes in environmental remediation applications.

This study investigates a green synthesis route for titanium dioxide (TiO2) nanoparticles (NPs) using Malabar spinach (Basella rubra) leaf extract, with graphene oxide (GO) as a dopant, for application as an electron transport layer in perovskite solar cells (PSCs). The synthesized TiO2 NPs were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS), and field emission scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (FESEM/EDX). XRD results confirmed the presence of a pure anatase phase with a smaller crystallite size than that of commercial TiO2, while EDX analysis verified the successful synthesis through elemental analysis. FESEM imaging revealed a mixture of rugged and uniformly distributed nanoparticles. Optical studies showed a reduced bandgap energy (3.0400 eV) compared to commercial TiO2 (3.2000 eV), indicating improved light absorption potential. The integration of GO suggestively enhanced photovoltaic performance, with the highest power conversion efficiency (0.2467%) observed in the sample synthesized using distilled water, leaf extract, and GO-an order of magnitude higher than commercial TiO2 (0.0259%). However, performance varied notably with different synthesis media, suggesting that solvent-specific interactions play a critical role in determining device efficiency. These findings demonstrate the viability of eco-friendly synthesis in developing functional nanomaterials and highlight the synergistic benefits of combining plant-based reductants and GO doping. The approach offers a promising pathway toward more sustainable and cost-effective PSC technologies; however, optimizing plant extract composition and nanoparticle morphology remains essential.

In this study, the influence of pH adjustment sequence during green synthesis on the structural evolution of TiO2 nanoparticles was investigated, specifically examining whether the solution pH was modified before or after the addition of titanium(IV) isopropoxide (TTIP). Jatropha multifida leaf extract was employed as a natural reducing, capping, and stabilizing agent owing to its rich bioactive compounds, which are capable of directing nanoparticle formation. Two synthesis pathways were systematically compared: pre-pH adjustment, where the extract pH (similar to 5) was adjusted to acidic or basic conditions prior to TTIP addition, and post-pH adjustment, where TTIP was first introduced into the extract, followed by pH modification. The pH values were varied at 3, 7, and 10. The results revealed that the crystallite size increased with increasing pH, and for the same pH value, the post-pH adjustment route consistently produced larger crystallites than the pre-pH adjustment route. Following synthesis, all as-prepared samples were utilized as photoano des in DSSCs, and their photovoltaic performance was evaluated via current-voltage (I-V) measurements under simulated solar illumination. The pre-pH 3 sample achieved the highest PCE of 5.52%, attributed to its smaller crystallite size, which provides a higher surface area, greater dye loading, and improved charge transport. Thus, the pre-pH adjustment method is more suitable for producing TiO2 for DSSC applications. This study demonstrates that the timing of pH adjustment controls TiO2 nucleation and growth, shaping its final structure, and affecting DSSC performance. It provides a simple, green, and scalable way to tune TiO2 for improved solar cell efficiency.

In this work, titanium dioxide nanoparticles (TiO2 NPs) were green-synthesized using jasmine (Jasminum sambac) flower extracts as the medium with different solvent variation concentrations. The green synthesis was carried out using titanium isopropoxide (TTIP) as a precursor via the sol-gel method. The obtained TiO2 NPs were characterized using infrared spectroscopy (FTIR), ultraviolet spectroscopy (UV-DRS), X-ray diffraction (XRD), field emission scanning electron microscopy/energy dispersive X-ray spectroscopy (FESEM/EDX), Raman spectroscopy, and high-resolution transmission electron microscopy/selected area diffraction (HRTEM/SAED). The characterization revealed that the green-synthesized TiO2 NPs possess a pure tetragonal anatase phase, which belongs to the space group I41/amd. Dye-sensitized solar cell devices were further fabricated using the obtained TiO2 NPs and sensitized with the commercial dye N719 and a kesumba (Bixa orellana) seed extract as an alternative, inexpensive, yet sustainable natural dye. The highest efficiency of 2.52% was obtained from TiO2 NPs sensitized using commercial dye N719 and synthesized using jasmine flower extract containing 30% acetylacetone, followed by one containing 50% acetylacetone, which is higher than that of commercial TiO2 (0.80%). The same materials sensitized using kesumba seed extract resulted in efficiency of 0.22%, 0.08%, and 1.22%, respectively. These findings offer insight and pave the way for more novel, environmentally friendly methods for developing green-synthesizing nanomaterials and natural dye derivatives, ultimately contributing to a sustainable future.

The thin-film deposition technique using spin coating offers a cost effective alternative to Chemical Vapor Deposition (CVD) and Physical Vapor Deposition (PVD). The spin-coating process requires precise control of the motor drive system to ensure that the rotational speed, measured in rotations per minute (RPM), aligns with the set point and remains stable. This study presents the design and development of a spin coater prototype to achieve uniform thin-film deposition. The control method employed utilizes a Proportional-Integral-Derivative (PID) algorithm, incorporating a polynomial approach with bias tuning. The PID control was chosen to achieve stable operation in a non-linear system. The performance of the non-linear PID control system is compared with an open-loop control system by evaluating the overshoot behavior. In the first experiment, a proximity sensor was tested to measure the spin coater motor's speed in an open-loop control configuration. The performance was evaluated using Mean Absolute Error (MAE) and Mean Absolute Percentage Error (MAPE) metrics, with results showing an MAE of 1358.6 RPM and a MAPE of 23.13% compared to a tachometer. In the second experiment, stepresponse testing was conducted using a closed-loop PID control system with a polynomial approach and bias tuning. Compared to the open-loop system, the closed-loop PID controller reduced overshoot to less than 3%. The RPM deviation between the spin coater and the tachometer was limited to <120 RPM within the targeted set-point range, approaching ideal conditions. The closed-loop control was tested within the 5000–9000 RPM range, where stable RPM regulation resulted in more uniform TiO₂ thin-film distribution on glass substrates. This study highlights the effectiveness of closed-loop PID control in achieving precise rotational control, which is essential for enhancing the quality of thin-film deposition.

This study reports the green sol-gel-hydrothermal synthesis of bi-metal Au-Y co-doped TiO2 using Uncaria gambir leaf extract as a catechin rich capping agent. X-ray diffraction confirmed phase pure anatase TiO2 after calcination at 500 degrees C, with crystallite sizes of-1-17 nm based on (101) reflections and slight shifts indicating substitution by Au3+ and Y3+ ions. UV-Vis diffuse reflectance spectroscopy revealed visible-light absorption enhancement and indirect band-gap narrowing from 3.16 to 3.04 eV. FE-SEM images showed agglomerated nanospherical structures (30-75 mu m) composed of smaller crystallites, while EDX analysis detected the presence of Au, Y, Ti, and O in co-doped samples. Under 365 nm irradiation, Au-3-Y-3/TiO2 exhibited superior antibacterial activity against Staphylococcus aureus ATCC 25923 and Salmonella sp., attributed to band-gap narrowing and reactive oxygen species generation. In addition, the best-performing co-doped sample achieved strong antioxidant capacity with similar to 89 +/- 0.1% DPPH scavenging (IC50 approximate to 45.3 mg L-1) and showed higher anti-inflammatory compared with undoped TiO2. The synergistic effect of Au-Y co-doping and plant-mediated synthesis produced eco-designed anatase TiO2 with tuned microstrain, crystallite size, and enhanced multifunctional bioactivity. These findings highlight the promise of Au-Y/TiO2 nanostructures as sustainable photocatalysts for biomedical applications. [GRAPHICS] .

The synthesis of carbonaceous materials for reduced graphene oxide (rGO) precursors using oil palm empty fruit bunches waste as a carbon source offers a sustainable solution for waste management in the palm oil industry while delivering high-performance materials. The oil palm empty fruit bunches were carbonized, followed by acid washing, pyrolysis with ferrocene (8%, 12%, and 16% variations), and ultrasonication to produce rGO. The structural, electronic, and morphological properties of the rGO were analyzed using various characterization techniques. The band gap values decreased with increasing ferrocene concentration, from 1.14 eV (8%) to 1.06 (16%), indicating enhanced electronic conductivity. XRD analysis revealed a crystal size increase from 11.3 nm (8%) to 181 nm (16%), while Raman spectroscopy showed a consistent D to G intensity ratio of 0.85, indicating reduced structural defects. SEM-EDS results demonstrated a carbon to oxygen atomic ratio of 4.38 (8%), 3.79 (12%), and 3.77 (16%), confirming successful reduction and improved carbon content. These finding highlight the potential of rGO synthesized from oil palm empty fruit bunches for applications in semiconductors, energy storage, and gas sensing, offering an innovative approach to sustainable materials development.

Li4Ti5O12 (LTO) has been a great subject in lithium-ion battery research due to its high safety and electrochemical stability. However, the exploration of novel doping strategies to enhance its electrochemical performance remains a topic of interest. While single doping strategies have been widely investigated, co-doping strategies involving multiple dopants have only received limited attention. Here, we investigate the performance improvement of LTO through an Mg- and Fe-co-doping strategy. Fe precursors derived from steel manufacturing waste were used as dopants. Experimental results reveal that the co-doped samples exhibit enhanced capacity, cycleability, and rate capability. The theoretical analysis also provides valuable information on the electronic and structural changes induced by Mg- and Fe-co-doping, elucidating the impact on lithium-ion diffusion and storage. This approach contributes to the sustainable utilization of industrial waste and offers a low-cost method for the improvement of electrode materials.