Two-dimensional 4H-SnS2 single crystals of several square millimeters were grown using chemical vapor transport method. A bulk 4H-SnS2 can be easily exfoliated into few-layer 4H-SnS2 using mechanical exfoliation technique. Few-layer and multilayer 4H-SnS2 of 3, 8, 13, 27, 43, and 71 monolayers were stably obtained in ambient. The Raman spectra of few-layer and multilayer 4H-SnS2 reveal a single dominant A1g Raman mode. The A1g Raman mode of few-layer 4H-SnS2 is redshifted and broadened with reduced layer number, indicating that the phonon confinement effect is layer-dependent. The Raman tensor of the few-layer 4H-SnS2 can be fixed with the phonon confinement effect. This effect also significantly influences the thermodynamic properties of few-layer 4H-SnS2. The results provide valuable insights for the design of next-generation photonic and thermoelectric devices based on 4H-SnS2.

Compared with traditional electrode materials, porous nanostructured electrodes can notably advance ion transport and electron conductivity, furthering the overall energy-storage competency. The development of various nanostructures with controlled porosity and their cost-effective synthesis processes can improve the performance of the existing energy-storage systems. Engineering porous nanomaterials with optimized porosity, heteroatom doping, high surface area, and excellent electrochemical performance remains a significant challenge in supercapacitors. Overcoming these challenges will enable the development of high-performance, cost-effective, and scalable energy-storage systems. This chapter discusses fruitful methods and outlines a roadmap for using porous nanostructured electrodes in energy-storage devices. The chapter includes the latest research on 1D, 2D and 3D porous nanostructures of metal oxides and their suitability for electrochemical activity. It also provides an overview of the current state-of-the-art for forming porous core–shell nanomaterials of metal oxides and recommends the future direction for using them in energy-storage applications.

Recent developments in photocatalysts have focused on enhancing photocatalytic activities to improve the degradation of toxic molecules present in sewage waters. While significant improvements in photocatalytic efficiency have been achieved, stability remains a critical challenge. Ensuring that photocatalysts maintain their performance over time is essential for practical applications in water treatment. Consequently, this study concentrates on Gd-doped BiFeO3 (Gd:BFO) photocatalysts synthesized using the spray pyrolysis technique. The performance of Gd:BFO thin film photocatalysts was evaluated for the degradation of methyl orange (MO) dye under solar irradiation. The fabricated thin films were characterized through X-ray diffraction, ultraviolet-visible spectroscopy, and scanning electron microscopy. Results showed that Gd doping in BFO decreased the water contact angle compared to undoped BFO, indicating improved surface wettability. Additionally, Gd doping reduces electron-hole recombination, leading to enhanced photocatalytic activity. Remarkably, the Gd:BFO photocatalyst achieved a maximum degradation efficiency of 98 % for MO within 60 min of solar irradiation, while BFO reached only 82 % under the same conditions. Moreover, Gd doping enhanced the stability of BFO photocatalyst during dye degradation, allowing for consistent photocatalytic performance over nearly 8 cycles.

Defect-rich CMO NF membrane deliver broadband light absorption, enhanced hydrophilicity, and efficient photothermal conversion. It maintains structural stability and effectively purifies saline and dye-contaminated water.

The growing global demand for freshwater and sustainable energy requires integrated technologies capable of addressing water-energy challenges in a single platform. Here, a multifunctional photothermal architecture is developed by integrating copper bismuth oxide (CuBi2O4; CBO) with a two-dimensional (2D) Ti3C2-F MXene (MX) to form a CBO@MX hybrid, enabling simultaneous solar desalination, electrokinetic energy generation, and salt harvesting. CBO@MX loaded onto a cellulose membrane, is designed to promote directional capillary flow, ensuring sustained saline water supply to the photothermal interface. Synergistic coupling between the semiconducting CBO and MX enables broadband light absorption and efficient conversion into heat, while interlocking nanochannels facilitate ion transport and electrokinetic potential generation through the formation of an electric double layer. Under AM 1.5G solar irradiation, the CBO@MX delivered a high evaporation rate of ∼1.68 kg m-2 h-1 and simultaneously produced a stable open-circuit voltage of ∼0.5 V without any external power input. Moreover, asymmetrical wettability induced self-driven saline water transport and controlled salt crystallization at the membrane periphery, effectively mitigating pore blockage, while enabling simultaneous salt harvesting. The CBO@MX hybrid membrane exhibited stable performance for twenty five consecutive desalination cycles. This study presents a scalable, low-cost, and sustainable strategy for integrating solar-driven desalination with energy harvesting, offering a promising route toward decentralized and off-grid water-energy nexus technologies.

Abstract Electrocatalytic processes for green energy production are of growing importance as they offer efficient energy conversion while maintaining environmental sustainability. In this context, transition metal oxyhydroxides (TMO x H y ) have emerged as highly promising electrocatalyst candidates due to their intrinsic oxygen redox activity, structural robustness, and abundance of earth-derived elements. This review comprehensively examines the important characteristics and requisite strategies of TMO x H y materials, emphasizing their critical influence on catalytic performance. Various enhancement approaches—including surface and compositional modulation, elemental doping with transition metals, non-metals, and carbon-based species, cocatalyst integration, heterostructure engineering, and nano structuring are systematically evaluated for their roles in improving catalytic activity and durability. In addition, the electrocatalytic behavior of TMO x H y materials across diverse electrolyte systems is analyzed. Finally, key challenges such as charge transfer limitations, long-term operational stability, and electrode corrosion are discussed, and future perspectives for advancing TMO x H y -based electrocatalysts toward sustainable energy conversion technologies are proposed.

In this work, a novel 2D-Bi2S3/1D-SnO2, n-n heterostructure thin film was employed as a pseudocapacitive photoanode for enhanced solar energy utilization, yielding a significant improvement in energy storage performance. The three-electrode system delivered an areal capacitance of 15.22 mF cm-2 in 1 M Na2SO4 electrolyte at 0.2 mA cm-2 under 1 sun illumination, achieving 33% enhancement compared to dark conditions. In addition, the fabricated Bi2S3/SnO2 & Vert;PEDOT:PSS asymmetric photo-assisted electrochromic supercapacitor device exhibited a maximum areal capacitance of 1.78 mF cm-2 at 0.06 mA cm-2, which represents a 2.5-fold increase over its performance in the dark (0.70 mF cm-2 at 0.06 mA cm-2). Under illumination, the device also showed an areal energy density (Ea) of 0.8 mWh cm-2 and areal power density (Pa) of 356 mW cm-2. The device retained excellent cycling stability, with capacitance retention of 82.2% and 77.2% at 0.2 mA cm-2 after 1000 GCD cycles under dark and illumination, respectively. Mechanistic investigations revealed that the intercalation/de-intercalation of Na+ ions into 2D Bi2S3 (Bi2S3 + xNa+ + xe- <-> NaxBi2S3) and SO42- ions into the PEDOT:PSS chain during the charge-discharge process were facilitated by photon-induced redox activity and efficient charge separation by SnO2 nanorods (NRs), thereby improving energy storage capability. This study underscores the potential of novel heterostructure design and material combinations for the development of next-generation photo-rechargeable supercapacitors, paving the way for self-powered electronic devices.

The increasing risk of misuse of hazardous chemicals underscores the need for advanced materials capable of their rapid and complete detoxification. In this study, we report the ultrasound-assisted solvothermal synthesis of highly porous Cu-Metal Organic Framework, Cu-MOF (Cu-3(BTC)(2), BTC = 1,3,5 benzenetricarboxylic acid) and its application for the detoxification of para-nitrophenyl diphenyl phosphate (p-NPDPP) nerve simulant. X-ray Diffraction (XRD) confirmed face-centred cubic crystalline phase, while Field Emission Scanning Electron Microscopy (FESEM) and Brunauer-Emmett-Teller (BET) revealed well-defined octahedral nanoparticle morphology with a surface area of similar to 863 m(2)/g. Cu-MOF demonstrated excellent thermal stability, precise chemical stoichiometry, and similar to 1.7 fold higher detoxification efficiency (similar to 96%) than bulk Cu-MOF (b-Cu-MOF) in pure acetonitrile solvent under neutral ambient (298 K) conditions. Kinetic analysis showed a pseudo-second-order adsorption, best described by the Langmuir isotherm, yielding a maximum adsorption capacity of 52.1 mg/g for p-NPDPP. Thermodynamic analysis (Gibbs Free Energy, Delta G(0) = -6.7 kJ/mol, Enthalpy Delta H-0 = 11.5 kJ/mol, and Entropy Delta S-0 = 59.1 J/mol & centerdot;K at 298 K) inferred a spontaneous and endothermic detoxification process. These findings highlight Cu-MOF as an exceptionally efficient and sustainable material for the remediation of toxic organophosphorus compounds.

Morphological optimization combined with electronic modulation provides a powerful approach for designing high-performance electrocatalysts for hydrogen evolution. In this study, the successive ionic layer adsorption and reaction (SILAR) technique was employed to prepare nickel boride phosphide (Ni-B-P) catalysts for the hydrogen evolution reaction (HER). By tuning the phosphorus-to-boron (P/B) precursor molar ratio during SILAR, the particle size, electron redistribution among elements, and the electronic environment surrounding the nickel active sites were effectively controlled. Among the prepared electrocatalysts, the NiBP2 electrode (P/B = 0.66) demonstrated exceptional HER activity, achieving an overpotential of 134 mV at 10 mA cm-2 and a Tafel slope of 93 mV dec-1 in alkaline solution. X-ray photoelectron spectroscopy (XPS) confirmed that the P/B precursor molar ratio influences electron density around Ni0, underscoring its role as a catalytically active site. The improved electron density of nickel, moderate growth of spherical nanoparticles, and high porosity collectively enhanced hydrogen evolution performance. Interestingly, the NiBP2 electrode delivered a hydrogen production rate of 772 mL h-1 in a prototype water electrolyser and maintained stable operation for up to 100 h, highlighting its promise as an efficient electrocatalyst for commercial hydrogen production.

The present investigation explored the impact of solvothermal reaction time on the adsorption properties of synthesized spinel ZnFe2O4 Nanoparticles (ZF NPs) and their photocatalytic activity for the degradation of congo red (CR) dye. The structure, morphology and chemical composition is identified for the synthesized ZF NPs. The reaction times for the solvothermal synthesis of ZF NPs were investigated at time intervals of 6 hrs and 18 hrs which are denoted as ZF-6 h and ZF-18 h respectively. The XRD confirms the formation of spinel-type ZF-6 h and ZF-18 h with crystallite size of 5.50 nm and 8.36 nm for ZF-6 h and ZF-18 h respectively. The FESEM image of ZF6 h exhibits microspheres, whereas in ZF-18 h NPs, the microspheres undergoes deformation. TEM analysis of ZF6 h revealed that the microspheres were consists of 8-10 nm size ZF-NPs. Raman spectroscopy and XPS studies indicates, the reaction time influence the occupancy with 64 % and 32 % of inversion of Zn2+ cations from tetrahedral to octahedral sites in ZF-6 h and ZF-18 h, respectively. The surface area of mesoporous ZF-6 h and ZF18 h are 138.29 m(2)/g and 128.41 m(2)/g respectively as confirmed using BET and BJH techniques. The CR dye adsorption capacity of 123.73 mg/g for ZF-6 h is higher compared to ZF-18 h (99.93 mg/g). The maximum dye removal efficiency evaluated for ZF-6 h NPs and ZF-18 h NPs was 87.33 % and 73.09 % respectively upon exposure of natural sunlight. The recyclability study identifies that ZF-6 h NPs remain stable for three degradation cycles. These results indicate that reaction time in solvothermal synthesis is sensitive to the morphology and physicochemical properties of ZF NPs. The enhanced performance of such ZF NPs is attributed to the synergistic effect of adsorption followed by photocatalytic (photo-Fenton) degradation of dyes.

Herein, we investigate structural and electronic properties of beta-Ga2O3 and p-type Ni-doped alpha-GaCrO3 (alpha-GaCrO3:Ni) heterostructure, focusing on its potential for charge separation and rectification mechanisms. Thin films are grown using the magnetron sputtering technique. Synchrotron-based high-resolution x-ray diffraction and high-resolution transmission electron microscopy reveals a sharp and high-quality interface between beta-Ga2O3/alpha-GaCrO3:Ni/Al2O3 epitaxial layers and also confirm single-crystal epitaxial growth of monoclinic (-201) beta-Ga2O3 along the [0001] direction of alpha-GaCrO3:Ni. Optical measurements confirm an average transmission of more than 70% for all thin film samples, showing their potential for transparent optoelectronic devices. Using synchrotron-based photoelectron spectroscopy, valence band offset and conduction band offset at beta-Ga2O3/alpha-GaCrO3:Ni interface are determined to be 2.44 +/- 0.2 and 1.44 +/- 0.2 eV, respectively, which confirms a type II (staggered gap) energy band alignment at the heterojunction. This type of band alignment is highly useful in a wide range of photovoltaic and optoelectronic devices where efficient charge separation, reduced recombination, and rectification of charge carriers play an important role, such as in solar cells, UV photodetectors, and many other optoelectronic devices. (c) 2025 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International (CC BY-NC-ND) license (https://creativecommons.org/licenses/by-nc-nd/4.0/). https://doi.org/10.1063/5.0284059

Efficient protocols for the synthesis of secondary amines using phenylboronic acid and aniline via Chan–Evan–Lam coupling reaction and secondary amides by oxidative amidation of aldehydes with aniline utilizing heterogeneous, recyclable MIL‐101(Cr)‐SB‐Cu catalyst have been developed. MIL‐101(Cr)‐SB‐Cu has been synthesized via post‐synthetic modification of amino‐functionalized MIL‐101(Cr). Various spectroscopic and analytical methods, such as FT‐IR, PXRD, SEM, TEM, EDX, XPS, ICP‐OES, and TG were used to characterize the synthesized catalyst. The catalyst showed excellent catalytic activity and provided good to excellent yields of the desired products under mild reaction conditions. The catalyst can be reused for up to five consecutive runs without significant loss in its catalytic activity. Low catalyst loading, easy work‐up, gram‐scale synthesis, and a simple catalyst preparation are some other advantages of this approach.

Here, we report synthesis of magnetic nanocomposite with zero-waste approach for organic pollutant removal and oxygen evolution reaction. The nanocomposite was synthesized using agriculture waste soaked with Co2+-Fe3+ metal ions at 900 °C and characterized using FESEM, HRTEM, PXRD, Zeta-potential, and VSM techniques. The nanocomposite shows an impressive adsorbent property for organic dyes (90-96 % removal), and pharmaceutical drug (paracetamol, 84% removal), along with individually used ‘hair dye’ (95% removal) in 5 min only. The recyclability of the nanocomposite demonstrates the practical benefits of the material for waste water remediation. Interestingly, after the adsorption, the generated secondary waste (exhausted dye adsorbed nanocomposite) is used as oxygen evolution reaction (OER) electrocatalyst. The dye-adsorbed nanocomposite shows good OER activity with an overpotential of 264 mV at 10 mA/cm2 with good stability upto 10 h. This study sheds light on the reuse and recycling of the secondary waste of the adsorption process to develop efficient OER electrocatalysts and shows a zero-waste approach towards the environment.

This study focuses on fabricating iron-based composites inspired by ancient corrosion-resistant structures like the Delhi iron pillar. For this, the directly reduced iron (DRI) is integrated with various percentages of slags (P2O5 + SiO2 and FePO4 + SiO2) and some with FePO4 supplement. Compared to the samples with low and high slag proportions, the sample with an intermediate slag proportion ( 18

This study systematically explores impact of impurity‐induced defects in MAX phase on MXene quality and, hence, electrochemical performance. Structural defects in impure MAX phase are transferred to derived MXene and disrupt ion transport pathways by creating non‐uniform interlayer spacing, thereby hindering ion diffusion and reducing electrochemical efficiency. Notably, as the purity of Ti 3 AlC 2 MAX phase increases from 47% to 99%, the interlayer spacing in MXene expands, significantly enhancing its electrochemical properties. Galvanostatic charge–discharge (GCD) measurements at 1 A g −1 reveal that the specific capacitance of MXene improves from 121.86 to 680.8 F g −1 with increasing MAX phase purity. Further enhancement to 918.5 F g −1 is achieved by incorporating carbon black (CB), which enhances the conductive network between MXene sheets. Symmetric battery‐type supercapacitor device assembled with CB@Ti₃C₂‐F electrodes exhibits specific capacity of 76.54 mAh g −1 (@1A g −1 ) over 1.65 V potential window, with energy density of 55.58 Wh kg −1 (@1A g −1 ) and power density of 1500.27 kW kg −1 (@10A g −1 ), surpassing previously reported values. Additionally, the device demonstrates excellent cycling stability, retaining 94% of its initial capacitance after 5000 charge–discharge cycles. This study underscores the critical role of MAX phase purity in regulating MXene interlayer spacing, thereby unlocking new opportunities for high‐performance hybrid energy storage systems.

Designing an active catalyst and an in situ route for the decoration of single atoms (SA) on graphitic carbon nitride (C 3 N 4 ) toward efficient photocatalytic H 2 evolution reaction has been a wide area of focus. However, ultralow loading of SAs and miniaturizing of the catalyst with excess nitrogen for maximized photocatalytic H 2 production from water remains challenging. Herein, a simple novel method is demonstrated to fasten ultralow concentration of Pt atom (0.08 wt.%) on template‐based N‐rich C 3 N 4 (C 3 N 4.6 ) via thermal polymerization and acid leaching method to get a visible light irradiation‐based H 2 production rate of 64100 µmol g −1 h −1 , with an apparent quantum yield of 25.3%, and long‐term stability. The synthesis process involves initially attaching platinum complex to SBA‐15, thermal polymerization of dicyandiamide, and the formation of Pt SAs anchored on the surface of C 3 N 4.6 . Pt SAs are found to coordinate and interact with the N‐rich sites and alter the electronic structure of the C 3 N 4.6 . The atomically dispersed Pt species not only act as a sink for photoexcited electrons but also work as reduction sites to facilitate the faster water reduction kinetics on the surface than Pt NP decorated C 3 N 4 , highlighting the potential of ultralow‐loading Pt‐SACs in promoting sustainable H 2 production.

Herein, we report the optimization of zero-dimensional (0D) nickel cobalt sulfide (NCS) nanoparticles and two-dimensional (2D) reduced graphene oxide (rGO) nanosheets as excellent electrodes for high-performance supercapacitors. The well-optimized NCS, rGO, and their composite taken in weight ratio of NCS-rGO(2:1) provides surface area of 40.02, 10.13, and 12.02 m(2)/g, respectively, which offers more active sites for electrochemical reactions. The augmented presence of +4 oxidation states of Co and the +3 oxidation state of Ni in the NCS-rGO(2:1) composite delivers high specific capacitance (C-s) values. Post electrochemical testing, NCS-rGO(2:1) exhibits an excellent C-s of 1202.57 F/g at 2 A/g and cyclic stability of similar to 80 % after 10,000 cycles at 5 A/g. Three different devices are prepared with symmetric and asymmetric configurations of NCS, rGO, and NCS-rGO(2:1) electrodes. The symmetric device NCS-rGO(2:1) shows the best performance in terms of C-s of 310.45 F/g at 2A/g. However, the asymmetric device with rGO and NCS-rGO(2:1) as electrodes delivered the highest energy density of 70.9 Wh/kg (at 16.1 kW/kg) and power density of 163.6 kW/kg (at 54.5 Wh/kg). Overall, our finding corroborates that rich redox active NCS-rGO(2:1) composites are excellent candidates to synergistically assist each other to provide supercapacitor devices with higher energy density.

This study presents a sustainable and efficient approach for wastewater remediation using pristine NiMn2O4 (NMO) spinel nanoparticles (NPs) as a photocatalyst to degrade toxic industrial dyes. Unlike conventional methods, the NMO NPs based system operates without requiring Fenton reagents (e.g., H2O2) or pH adjustments, offering a cost-effective, scalable, and environmentally friendly solution. The NMO NPs were synthesized via a simple co-precipitation route and exhibit a tetragonal crystalline structure, with an average particle size of -100 nm, high surface area (-3.32 m2/g), and a visible-light-responsive bandgap of 1.75 eV. Under Xenon (Xe) lamp irradiation, these NMO NPs demonstrated exceptional photocatalytic degradation efficiency, achieving over 93 % removal of both cationic dyes (Crystal Violet (CV) and Malachite Green (MG)) and anionic dyes (Acid Fuchsin (AF) and Rose Bengal (RB)) within 180 min. The apparent rate constants for CV and MG degradation were calculated to be 0.013 and 0.014 min- 1, respectively. Radical scavenging experiments indicated that hydroxyl (center dot OH-) and superoxide (center dot O-2 ) radicals played dominant roles in the degradation mechanism. Furthermore, LC-MS analysis revealed the stepwise degradation pathway of MG, involving demethylation, hydroxylation, oxidation, and deamination, leading to harmless by-products. This work establishes pristine NMO as a promising, reagentfree photocatalyst for real-world dye contaminated water treatment applications.

Nickel cobalt sulfide (NiCo2S4; NCS) is known for its notable inherent electronic conductivity and high theoretical capacity, attributed to its excellent redox behavior. However, developing well-defined hierarchical nanostructured NCS with ample electroactive interfaces remains a persistent challenge. In this study, we report reaction time-dependent hydrothermal synthesis of NCS nanoparticles, which transform into nanoflakes under controlled reaction conditions. With extended reaction duration, these nanoflakes further interlinked to form hierarchical discs and micro-flowers like morphologies. The cubic crystalline NCS nanostructures with larger specific surfaces and Ni2+/Ni3+, Co3+/Co2+, and S2-oxidation states exhibit remarkable electrochemical redox activity in alkaline electrolyte. NCS micro-flowers composed of interlinked 2D nanoflakes (NCS10) exhibit specific capacitance (Cs) of 1062.7 F g-1 at current density of 1 A g-1 and Cs retention of 93.5 % after continuous 5000 GCD cycles in three-electrode configuration. When employed in a symmetric solid-state battery-type supercapacitor, the NCS10 electrode delivered Cs of 72.52 F g-1 at 1 A g-1 and maximum energy density (Ed) of 17.02 Wh kg-1 and power density (Pd) of 5.02 kW kg-1. The 2-electrode device also offered satisfactory longterm stability with 86.27 % retention after 1000 cycles. Our study elucidates the critical role of morphology in enhancing the electrochemical performance of Ni-Co sulfide electrodes, highlighting their real-time potential for high-performance supercapacitors.

Sulfur mustard (SM) poses serious threats of intentional use against civilians, so it requires utmost and immediate attention for detoxification. Therefore, Metal-Organic Framework-5 (MOF-5), Graphene Oxide (GO), and MOF-5@GO composite materials are explored for effective detoxification of SM. The crystalline MOF-5@GO, having cubic morphology with a porous structure and abundant functional sites due to surface modification, is found to be responsible for the efficient adsorption of SM. Thermally stable MOF-5@GO consisting of Zn, C, and O in their stoichiometric form exhibits a high active surface area of similar to 407.38 m(2)/g, which provides more accessible sites for adsorption of SM and, thereafter, detoxification. The synergistic interactions between MOF-5 and GO in the MOF-5@GO composite delivered 92 % adsorption for the SM, which is similar to 2.5 and similar to 1.6 times higher than pristine GO and MOF-5, respectively. The adsorptive removal of SM exhibits pseudo-first-order kinetics with rate constant (k), half-life (t(1/2)), and maximum adsorption capacity (q(max)) of 24.66 x 10(-2)/h, 2.81 h, and 18.01 mg/g, respectively. The GC-MS analysis reveals better degradation of sulfur mustard into relatively non-toxic thiodiglycol, etc., products for the MOF-5@GO composite. Therefore, MOF-5@GO is a very efficient and eco-friendly contender for outstanding performance in detoxifying highly hazardous SM.