The treatment of industrial wastewater containing multiple heavy metals (MHMs) remains challenging, primarily because conventional adsorbents suffer from poor stability, limited adsorption capacity in mixed-metal systems, or high energy consumption during synthesis. To address these issues, this study employed a room-temperature in-situ impregnation method to load NH2-MIL-100(Fe) onto amine-functionalized magnetic hydrochar (HBAP). Three highly dispersible magnetic composites, designated as NM-100-HBAP-X (X = 0.75, 1, 1.25), were synthesized by adjusting the mass ratio of NH2-MIL-100(Fe) to HBAP. Experimental results demonstrated that the optimal material (NM-100-HBAP-1) exhibited high adsorption capacities for Pb(II), Cd(II), and Cr(VI) in a mixed-metal system. The maximum adsorption capacities determined by the Langmuir model were 181.13, 175.02, and 158.69 mg/g for Pb(II), Cd(II), and Cr(VI), respectively, which are comparable to previously reported values for hydrochars or MOF-based materials. Mechanistic analysis revealed that amino groups facilitate a synergistic process by reducing Cr(VI) to Cr(III), which is then immobilized via complexation and co-precipitation, thereby further enhancing Cd(II) removal. The material also demonstrated good cycling stability, retaining over 50

The global chlortetracycline (CTC) production capacity stands at approximately 110,000 tons per year, which poses severe threats to ecosystems and human health. To address this challenge, this study firstly presents the in-situ synthesis of endogenous oxalate-derived FeC2O4 supported on FeC2O4/HC for the efficient photocatalytic degradation of CTC. FeC2O4/HC achieved 92.7 % CTC degradation within 150 min at pH 8 without any activators, representing 5.15 times higher than pristine hydrochar (HC), along with a 50.2 % total organic carbon (TOC) removal rate. The formation of FeC2O4 optimized the band structure of HC enhanced electron transfer and promoted surface C-O group formation and furan ring polymerization, which continuously generated reactive oxygen species (& sdot;O2-and h+) for CTC degradation. The synergistic effect of Fe doping and HC coating endowed the catalyst with excellent stability, enabling efficient operation across a broad pH range (pH = 4-10). The T.E.S. T. software was employed to evaluate the ecotoxicity of degradation intermediates, confirming the complete decomposition of CTC into H2O and CO2. Furthermore, mung bean hydroponic experiments verified that FeC2O4/ HC exhibited no phytotoxicity. This work provides a green, efficient catalyst strategy for mitigating antibiotic pollution.

Constructing catalysts with highly dispersed active sites in a photocatalytic-peroxymonosulfate (PMS) system is crucial for the efficient removal of chlortetracycline (CTC) from water. In this study, Co-C3N5 (n%) with abundant and highly dispersed active sites was synthesized by liquid-phase mixing followed by one-step calcination, achieving in situ doping of varying proportions of Co(NO3)2 center dot 6H2O into the C3N5 lattice with minimal energy consumption. The Co-C3N5(50%)/PMS/Vis system achieved a CTC degradation rate of nearly 95% within 5 min and the final mineralization rate of approximately 50%. Furthermore, the solution approached neutral conditions after reaction in real water matrices, benefiting aquatic ecological balance and demonstrating substantial progress toward practical photocatalyst implementation. After five cycles of treatment, the degradation efficiency remained above 85% with no cobalt leaching, demonstrating good reusability and stability. 1O2, h+, and O2 center dot- were identified as the primary active species in the degradation process. The Co2+/Co3+ cycle continuously activates PMS, while the highly dispersed Co active sites enable rapid and efficient degradation. Based on LC-MS analysis and T.E.S.T assessment, three degradation pathways of CTC were proposed, and the intermediates were demonstrated to be non-toxic. Moreover, using Chlorella as an ecological indicator, Co-C3N5 effectively reduce the aquatic toxicity of CTC. Finally, a life cycle assessment (LCA) shows that Co-C3N5 outperforms other emerging photocatalysts as a low-carbon option. This green, low-carbon, and environmentally benign photocatalyst offers a sustainable solution for translating laboratory research to practical antibiotic remediation in industrial applications.

Microplastics (MPs), as emerging contaminants, originate from diverse sources and accumulate across various environmental media, posing potential risks to both ecosystems and human health. Optical detection techniques have emerged as a primary and efficient approach for MPs analysis due to their high sensitivity, accuracy, environmental friendliness, efficient, non-destructiveness and high specificity. This review systematically summarizes recent advances in optical methods for MPs detection, with a focus on two major methodological pathways: spectroscopic detection and fluorescence-based detection methods. For spectroscopic methods, the principles, advantages, limitations and practical applications of Raman spectroscopy and infrared spectroscopy are discussed specifically. Additionally, the significant contributions of machine learning (ML)-enhanced spectroscopic methods in improving MPs identification accuracy and spectral data processing efficiency were highlighted. For fluorescence-based detection, a comprehensive overview is provided on detection strategies employing fluorescent staining like Nile red (NR) for MPs in diverse environmental settings, as well as recent improvements in novel dyes designed to enhance sensitivity and anti-interference capabilities. The unique advantages of carbon dots (CDs) and carbon nitride materials as fluorescent labels for specific MPs identification and environmental behavior tracing are also critically evaluated. Through Comparing the detection principles, practical performance, strengths and limitations of various methods, theoretical support and methodological guidance are provided for the continual optimization of MPs detection technologies and the precision of environmental monitoring.

The intrinsic capacitor characteristic of the triboelectric nanogenerator (TENG) raises a significant challenge in achieving high energy harvesting efficiency. Power management has been treated as one of the most promising way to address this problem. Different from management only by traditional rectifier bridge, passive power management is more in line with the actual scenario of energy harvesting since it can eliminate the dependence on an external power supply. In this work, it introduces an innovative passive power management circuit (PMC) that employs cycles for maximized energy output strategy (CMEO) and unidirectional LC oscillation. Simulation results show that the proposed PMC can shorten the charging time to a 47 mu F capacitor by 88.3 %, and increase the effective output power at 1 M Omega by 17.35 times. The sources of energy loss are revealed by numerical analysis for energy transfer. Furthermore, the relationship between these losses and semiconductor device selection is investigated through simulation, and further validated experimentally. This contributes to improving the power management performance and expanding the range of available TENGs. Through optimizing device selection, the fabricated PMC operates efficiently for a TENG with maximized effective output of 6.7 mu W, and its excellent adaptable potential to various TENGs is demonstrated.

Hydrolysis of InN film was employed for synthesis of a self-powered In(OH)3/InN heterostructure photodetector. This novel heterostructure exhibited high performance in detecting white light in self-powered mode. The method eliminates the need for additional processing steps and equipment, thereby streamlining the overall process and reducing costs. The result presents a promising approach for the development of innovative photodetectors by integrating In(OH)3 nanostructures on InN. This research provides a promising strategy for the development of innovative photodetectors using InN film, thereby expanding the scope of potential applications in photoconversion technologies.

A highly dispersed Fe in situ doped C3N5 (Fe-C3N5) photocatalyst utilizing inorganic iron salt was successfully prepared, which was applied in photocatalytic synergistic advanced oxidative degradation of chlortetracycline (CTC) under the activation with persulfate. BET measurements revealed that uniform Fe doping increases the specific surface area, thus enhancing the reactive active sites. Photoelectric tests indicate that Fe doping optimizes the energy band structure of C3N5, thereby enhancing electron transfer, and the photogenerated electrons facilitate the Fe2+/Fe3+ redox cycle, which is beneficial for the sustained and efficient activation of persulfates. The Fe-C3N5(50 %)/PMS/Vis system achieved over 95 % degradation of CTC within 2 h, after four cycles, the Fe-C3N5(50 %) still exhibits good reusability and stability. Free radical quenching experiments coupled with EPR spectroscopy identified 1O2, h+, and ·O2- as the dominant reactive species driving the degradation of CTC, elucidating the potential degradation mechanisms. Based on LC-MS measurements and utilizing the TEST toxicity assessment software, it has been determined that CTC ultimately decomposes into non-toxic small molecules, such as CO2 and H2O. Furthermore, a hydroponic germination experiment using mung beans was conducted to demonstrate that Fe-C3N5(50 %) does not exhibit toxic effects on plant growth. Importantly, this study offers novel insights into the green synthesis of highly dispersed Fe doping C3N5 photocatalytic for the efficient degradation of CTC.

Two-dimensional transition metal carbon nitrides (MXenes) are a prominent class of functional materials with significant potential for sensing applications. However, their conventional charge transfer mechanisms pose limitations for detecting nitrogen dioxide (NO2). In this study, we successfully design-synthesized potassium titanate (KTO) nanoribbons by oxidizing and alkalizing monolayer Ti3C2Tx MXene, targeting room-temperature NO2 detection. The Ti3C2Tx-derived KTO exhibited exceptional selectivity for NO2, achieving a remarkable response of 649.2 % for 50 ppm NO2, which is 550 times higher than that of the Ti3C2Tx sensor (1.18 %). Additionally, the sensor demonstrated a detection limit as low as 5 ppb at room temperature, along with rapid response (1 s) and recovery times (2 s), and excellent linearity. Computational analysis showed that the abundant OH groups on the KTO surface contribute to strong selective adsorption (2.79 |eV|) and efficient electron transfer (0.91 |e|) for NO2. The unique proton conduction mechanism of KTO further reduced the activation energy for proton transport, enhancing NO2 sensing performance. This study highlights the potential of Ti3C2Tx -derived KTO nanomaterials for advanced room-temperature NO2 detection and sensor technology development.

Elemental mercury (Hg0) molecules have received great attention as a neurotoxic environmental pollutant. However, the chemical inertness of Hg0 molecules hinders discovery by gas sensors. In this work, we explore the gas sensing property of Hg0 molecules on black phosphorene nanosheets. The results show that the Hg0 molecules can form chemical adsorption on the black phosphorene nanosheet with a suitable adsorption energy of 0.85 eV. Chemical bonds can be formed between Hg0 molecules and the black phosphorene nanosheet via the orbital interaction. Although the chemical adsorption slightly changes the band gap of 0.08 eV and the work function of 0.11 eV, the adsorption of Hg0 molecules will remarkably influence the behavior of frontier orbitals. The difference of electron effective mass decreases from 9.54 to 6.82 times between armchair and zigzag directions; as a result, when applying a bias of 2.0 V, the anisotropy of current remarkably decreases from 41.34 to 7.67 times between armchair and zigzag directions, which can be an effective response signal to detect Hg0 molecules. This work not only reports a gas sensor for Hg0 molecules but also provides a physical factor of anisotropy to monitor environmental pollutants.

The research presented herein explores the development of a novel Fe-MOFs-induced Fe doped C3N5 (Fe-C3N5) photocatalyst with good dispersion, high exposure Fe active sites, and environmental green friendliness, designed specifically for improved treatment efficiency of co-existing multiple tetracycline antibiotics (CM-TCs) in water. Under the visible light, Fe-C3N5 was used to degrade chlortetracycline (CTC) and CM-TCs in water by activating peroxymonosulfate (PMS). The degradation efficiency of Fe-M101-C3N5(15 %) could reach 96 % for CTC and 88 % for CM-TCs. The results of X-ray photoelectron spectroscopy (XPS), electron spin resonance spectroscopy (ESR) and radical quenching experiments demonstrated that the redox cycling between Fe3+ and Fe2+, along with the generation of reactive oxygen species (1O2, h+ and O2 & sdot;-), constitutes the core mechanism enabling efficient photocatalytic degradation of CM-TCs in the Fe-M101-C3N5(15 %)/PMS/Vis system. The density functional theory (DFT) calculation showed the materials had strong oxygen adsorption capacity. Chosen CTC as a typical representative, the three possible degradation pathways of CTC were investigated through liquid chromatograph mass spectrometer (LC-MS), which revealed that CTC would ultimately evolve into non-toxic and harmless small-molecule compounds, including COB and HBO. Toxicity estimation software (T.E.S.T) also predicted that the toxicity would gradually reduce during the degradation process of CTC.

Dopamine (DA) plays a critical role in various neurological disorders, including Parkinson's disease and schizophrenia, making its accurate and ultra-sensitive detection crucial for early diagnosis and treatment. In this study, a novel electrochemical sensor for DA detection was developed using monolayer Ti3C2Tx Mxene material treated with oxygen plasma. The oxygen plasma treatment significantly enhanced the surface activity and electronic transport capabilities of Ti3C2Tx, resulting in an ultra-low detection limit of 0.005 nM for DA. Electrochemical tests demonstrated the sensor's excellent sensitivity, stability, and performance. To further elucidate the underlying mechanisms of enhanced electrochemical performance, density functional theory (DFT) calculations were employed to investigate the impact of oxygen plasma treatment on the electronic structure of Ti3C2Tx. The DFT results revealed that the oxygen plasma treatment notably increased the number of active sites by introducing more oxygen-terminated functional groups on the surface of Ti3C2Tx. These oxygenated functional groups acted as catalysts, lowering the activation energy required for DA electrochemical reactions. Additionally, the oxygen plasma treatment effectively reduced the lattice constant of Ti3C2Tx, improving its internal electronic transport properties and thus enhancing its conductivity. The theoretical studies are in strong agreement with the experimental results, providing a clear understanding of the interaction between DA molecules and the oxygen-functionalized Ti3C2Tx surface. This research highlights the potential of oxygen plasma-treated Ti3C2Tx as a high-performance electrochemical sensing material and offers new perspectives for the development of sensitive biosensors.

The development of highly efficient nitrogen dioxide (NO2) sensors with excellent performance and low concentration detection capabilities is urgently needed for environmental monitoring and human health protection. In this study, In2O3 nanocubes and SnS2 nanoflower composites were assembled by hydrothermal method, achieving ultrasensitive detection of NO2. The gas sensing test results indicate that the 7 wt% In2O3/SnS2 sensor exhibits significant NO2 gas sensing performance, with a high response value of 15.61 for 5 ppm NO2, which is approximately 5 times that of the SnS2 sensor (3.12). Additionally, the 7 wt% In2O3/SnS2 sensor demonstrates good response and recovery times (34 and 65 s, respectively), along with excellent cross-selectivity, humidity resistance, repeatability, and long-term stability. Moreover, this sensor achieves ppb-level detection of NO2. The excellent gas sensing performance is attributed to the 7 wt% In2O3/SnS2 flower-like hierarchical structure owing to a large surface area and abundant active sites, as well as the n-n heterojunction that improves carrier mobility and enhances the gas sensing performance. The adsorption energy, charge transfer, and density of states of In2O3/SnS2 adsorbed NO2 system were analyzed using density functional theory (DFT) to explore the mechanism of gas sensing enhancement. Thus, the In2O3/SnS2 sensor paves the way for future real-time and rapid detection of NO2 gas.

Innovative education is essential for cultivating highly skilled innovative talents.Integrating cutting-edge scientific research findings and methodologies into classroom teaching can offer students a more comprehensive,practical,and forward-looking educational experience.This experimental design encompasses the steps of constructing crystal structure models,optimizing crystal structures,calculating band structures,and catalyzing compound decomposition in computational materials science.It aims to help students grasp the fundamental principles,processes,and analytical methods of first principles calculations,connect theory with practical engineering problems,and nurture their ability to employ modern engineering tools and novel technologies to identify,analyze,and resolve intricate engineering problems.

The increasing urgency to reduce atmospheric CO2 emissions has driven research into sustainable carbon sequestration technologies, with hydrochar (HC) emerging as a promising material. HC is derived from hydrothermal carbonization (HTC), a thermochemical process that converts biomass into a carbon-rich solid at moderate temperatures and self-generated pressure in an aqueous environment. Due to its unique reaction pathways, HC differs significantly from biochar (BC) derived from pyrolysis in terms of application, performance, and structural characteristics. Despite HC’s potential for long-term carbon storage, critical gaps remain in understanding its sequestration mechanisms, influencing factors, and optimization strategies—hindering its effective application. This review critically evaluates HC’s carbon sequestration capacity, focusing on overlooked complexities that influence its performance. Key parameters, including feedstock composition, reaction temperature, pH, and residence time, are systematically examined to elucidate their impact on HC’s structural integrity and carbon stability. Special attention is given to the role of lignin in enhancing stability and thermal resilience, as well as the concept of carbon-ash recalcitrance, where mineral embedding enhances carbon stability. To assess HC’s long-term sequestration effectiveness, this study analyzes key indicators such as thermal stability, chemical resilience, aromaticity, and dissolved organic carbon (DOC) leaching.Besides, this review explores innovative strategies for improving HC’s sequestration performance, including HTC liquid recycling, chemical modification, and salinity control. By integrating expert-driven insights and identifying research gaps, this synthesis advances theoretical understanding while outlining future directions for optimizing HC as a sustainable carbon sink. Ultimately, this work establishes HC as a critical material in global carbon management efforts and climate change mitigation.

Two-dimensional transition metal carbides and nitrides (Ti3C2Tx MXene) have garnered significant attention for gas sensing applications due to their high surface area and exceptional electrical conductivity. However, simultaneously achieving high sensitivity, stability, and rapid response in MXene-based gas sensors remains a critical challenge. In this study, we report the in-situ growth of sodium titanate (NTO) nanoribbons on MXene, forming a unique MXene/NTO heterostructure that enables highly sensitive and selective detection of nitrogen dioxide (NO2) at parts-per-billion (ppb) levels under ambient conditions. The MXene/NTO sensor delivers an outstanding response (S = 808.6 % at 50 ppm NO2) with an ultrafast response time of ∼1 s. Even at 5 ppb, it demonstrates a fully reversible resistance signal with negligible power consumption. Mechanistic investigations attribute this exceptional performance to surface proton conduction in NTO and the interfacial electric field at the MXene/NTO junction, which enhance charge transfer and NO2 adsorption. These findings establish MXene/NTO heterostructures as a versatile platform for next-generation room-temperature gas sensing technologies.

A heterocomposite structure offers significant advantages for enhancing the gas sensing performance of metal oxide-based sensors. In this study, In2O3/SnO2 heterocomposite fibers were fabricated by electrospinning. In2O3/SnO2 heterocomposite fibers show excellent gas sensing performance for acetone. The response of the In2O3/SnO2 sensor is 9.3-100 ppm acetone, markedly outperforming sensors made solely of SnO2 or In2O3. To clarify the improved mechanism, the adsorption behavior of In2O3/SnO2 for acetone was studied based on Density Functional Theory (DFT). The adsorption energy of In2O3/SnO2 for acetone at the optimal adsorption site is 0.89 |eV|, which is 0.18 |eV| and 0.04 |eV| higher than that of SnO2 and In2O3, respectively. Additionally, the electron transfer numbers of acetone to In2O3/SnO2 are also 0.08|e| and 0.05|e| greater than those of SnO2 and In2O3, respectively. The n-n heterojunction of In2O3/SnO2 alters the material's barrier, significantly enhancing carrier concentration and electron transfer. This n-n heterojunction is key to the improved gas sensing performance of the In2O3/SnO2 sensor for acetone. Therefore, In2O3/SnO2 heterocomposite fibers have great application potential in the field of gas sensors.

The antibiotic tetracycline (TCH) is a common pollutant seen in industrial wastewaters and municipal wastewaters, which poses an environmental problem. To solve this, oxygen modified carbon nitride (O-C3N4) and a Ztype heterojunction O-C3N4/Bi2Mo2O9 with excellent photocatalytic performance was constructed. The degradation efficiency of O-C3N4/Bi2Mo2O9-60 % for TCH (10 mg/L) was as high as 89.9 % under 3 h of illumination. The corresponding degradation rate was 1.9 and 3.1 times higher than that of O-C3N4 and Bi2Mo2O9, respectively, due to the effective carrier separation and the increased specific surface area. The Z-type heterojunction construction of the O-C3N4/Bi2Mo2O9-60 % composite and corresponding TCH degradation mechanism were further assessed through exploring the electron transfer, active radical and reaction paths. Furthermore, the OC3N4/Bi2Mo2O9-60 % composite exhibited a high cyclic stability, and its degradation efficiency remained at 87.5 % after 5 cycles. The O-C3N4/Bi2Mo2O9-60 % composite also had excellent adaptability to the actual aqueous environment, and the degradation efficiency for TCH in different actual aqueous environments remained above 70 %. All results indicated that O-C3N4/Bi2Mo2O9 composites have significant visible photocatalytic performance and can be used for the practical removal of TCH pollutant.

Two-dimensional transition metal carbon nitrides (MXenes) are a prominent class of functional materials with significant potential for sensing applications. However, their conventional charge transfer mechanisms pose limitations for detecting nitrogen dioxide (NO2). In this study, we successfully design-synthesized potassium titanate (KTO) nanoribbons by oxidizing and alkalizing monolayer Ti3C2Tx MXene, targeting room-temperature NO2 detection. The Ti3C2Tx-derived KTO exhibited exceptional selectivity for NO2, achieving a remarkable response of 649.2% for 50 ppm NO2, which is 550 times higher than that of the Ti3C2Tx sensor (1.18%). Additionally, the sensor demonstrated a detection limit as low as 5 ppb at room temperature, along with rapid response (1s) and recovery times (2s), and excellent linearity. Computational analysis showed that the abundant OH groups on the KTO surface contribute to strong selective adsorption (2.79 |eV|) and efficient electron transfer (0.91 |e|) for NO2. The unique proton conduction mechanism of KTO further reduced the activation energy for proton transport, enhancing NO2 sensing performance. This study highlights the potential of Ti3C2Tx -derived KTO nanomaterials for advanced room-temperature NO2 detection and sensor technology development.

Nitrogen dioxide (NO2) is a significant environmental and human health hazard. Current NO2 sensors often lack sensitivity and selectivity under ambient conditions. This study investigates ammonia pyrolysis modification of monolayer Ti3C2Tx MXene to enhance NO2 detection at room temperature. Nitrogen-doped Ti3C2Tx demonstrates a substantial improvement in sensitivity, with a response of 8.87% to 50 ppm of NO2 compared to 0.65% for the original sensor, representing a 13.8-fold increase. The nitrogen-doped sensor also exhibits superior selectivity and linearity for NO2 under ambient conditions. Theoretical analysis shows that nitrogen incorporation promotes enhanced interaction between Ti3C2Tx and its surface oxygen-containing functional groups through electronic hybridization, resulting in improved adsorption energy (1.80 |eV|) and electron transfer efficiency (0.67 |e|) for NO2, thereby enhancing its gas-sensing performance. This study highlights the potential of ammonia pyrolysis-treated Ti3C2Tx MXene for advancing NO2 sensor technologies with heightened performance at room temperature.