118 research outputs found
Enhanced removals of micropollutants in binary organic systems by biomass derived porous carbon/peroxymonosulfate
No full textWater pollution usually involves multiple pollutants, and their degradation mechanisms are complicated. In this study, we investigated the degradation of single and binary pollutants (phenol and p-hydroxybenzoic acid (HBA)) in water, using biomass-derived N-doped porous carbon (Y-PC) for peroxymonosulfate (PMS) activation and we found better kinetics and efficiencies of degradation in binary pollutants than single pollutant systems. Electron paramagnetic resonance (EPR), quenching experiments, and electrochemical tests indicated that •OH, SO4•−, O2•−, and 1O2 accounted for the catalytic oxidation of phenol/HBA, while the electron-transfer pathway had an additional contribution to phenol degradation. We unveiled that the HBA degradation rate was similar in the binary and single systems due to the non-selective attack of the micropollutants by •OH, SO4•−, O2•− and 1O2. However, phenol degradation rate was significantly accelerated in the binary phenol/HBA system as compared to that in the single phenol solution, due to the exclusive and selective role of electron transfer pathway. In the binary micropollutant system, a fortified electron-transfer pathway over phenol directly expedited its decomposition and contributed indirectly to this process. This study provides new insights into porous carbon-based advanced oxidation processes for the simultaneous removal of multicomponent contaminants in practical applications.Wenjie Tian, Jingkai Lin, Huayang Zhang, Xiaoguang Duan, Hongqi Sun, Hao Wang, Shaobin Wan
Nano-sized FeVO4·1.1H2O and FeVO4 for peroxymonosulfate activation towards enhanced photocatalytic activity
No full textVisible-light-assisted catalytic peroxymonosulfate (PMS) activation is an effective advanced oxidation technique for removing organic pollutants from water. Here, nano-sized fervanite FeVO4∙1.1 H2O (FV-H) and FeVO4 (FV-A) with regulated structures are synthesized at different pH values or annealing temperatures for photocatalytic methylene blue (MB) degradation via PMS activation. The activation mechanisms induced by FV-H and FV-A photocatalysts are examined by radical quenching, electron paramagnetic resonance (EPR) tracing methods, and (photo) electrochemical characterization. Our findings indicate that the multiple PMS activation pathways by photogenerated charge carriers from photocatalysts, as well as Fe(II)/Fe(III) and V(IV)/V(V) mixed-valence ion pairs led to the production of reactive holes (h+), hydroxyl (•OH) and sulfate radical (SO4•−) in FV-H (or FV-A)/PMS/Vis system for photodegradation, while SO4•− worked dominantly for MB degradation. The influences of PMS dosage, inorganic anions, pH value, and MB concentration on the degradation rates are also investigated. This work offers a new thought to the synthesis of high-efficiency photocatalysts for practical water treatment.Di Li, Zhengxin Yao, Jingkai Lin, Wenjie Tian, Huayang Zhang, Xiaoguang Duan, Shaobin Wan
Confined Tri-Functional FeOx @MnO2 @SiO2 Flask Micromotors for Long-Lasting Motion and Catalytic Reactions
No full textH2O2-fueled micromotors are state-of-the-art mobile microreactors in environmental remediation. In this work, a magnetic FeOx@MnO2@SiO2 micromotor with multi-functions is designed and demonstrated its catalytic performance in H2O2/peroxymonosulfate (PMS) activation for simultaneously sustained motion and organic degradation. Moreover, this work reveals the correlations between catalytic efficiency and motion behavior/mechanism. The inner magnetic FeOx nanoellipsoids primarily trigger radical species (• OH and O2 •−) to attack organics via Fenton-like reactions. The coated MnO2 layers on FeOx surface are responsible for decomposing H2O2 into O2 bubbles to provide a propelling torque in the solution and generating SO4 •− and • OH for organic degradation. The outer SiO2 microcapsules with a hollow head and tail result in an asymmetrical Janus structure for the motion, driven by O2 bubbles ejecting from the inner cavity via the opening tail. Intriguingly, PMS adjusts the local environment to control overviolent O2 formation from H2O2 decomposition by occupying the Mn sites via inter-sphere interactions and enhances organic removal due to the strengthened contacts and Fenton-like reactions between inner FeOx and peroxides within the microreactor. The findings will advance the design of functional micromotors and the knowledge of micromotor-based remediation with controlled motion and high-efficiency oxidation using multiple peroxides.Yangyang Yang, Lei Shi, Jingkai Lin, Panpan Zhang, Kunsheng Hu, Shuang Meng, Peng Zhou, Xiaoguang Duan, Hongqi Sun, and Shaobin Wan
Temperature-Induced Variations in Photocatalyst Properties and Photocatalytic Hydrogen Evolution: Differences in UV, Visible and Infrared Radiation
No full textIn this work, solar-heating-induced temperature-based photocatalytic hydrogen evolution reaction (PC-HER) of different photocatalysts (TiO₂ P25, g-C₃N₄, and their loaded Pt) was comprehensively studied and analyzed with the assistance of a series of temperature-based in situ characterizations. It was found that pristine TiO₂ P25 and g-C₃N₄ displayed enhanced PC-HER performances with increasing temperature (25–65 °C), while their loaded Pt nanoparticles (NPs) demonstrated a different behavior under ultraviolet (UV) or visible irradiation, presenting the highest hydrogen evolution rate at 35 °C. More interestingly, Pt NPs-g-C₃N₄ showed increasing PC-HER performances from 25 to 65 °C under visible light irradiation. Characterizations suggested that lowered electrical impedance, reduced band gap, increased light absorption, and elongated photoelectron lifetime with increased temperature are beneficial for improved PC-HER. However, agglomeration of Pt NPs significantly deteriorated the PC-HER performance at higher temperature and UV light can aggravate the thermal agglomeration of Pt NPs.Xiaojie Li, Jingkai Lin, Jiaquan Li, Huayang Zhang, Xiaoguang Duan, Hongqi Sun, Yingping Huang, Yanfen Fang, and Shaobin Wan
Polyaniline-Facilitated Direct Electron Transfer from Photosystem II on Inverse-Opal CeO₂
No full textOnlinePublIntegrating natural photosystem II (PSII), the only enzyme that oxidizes water, with artificial electrodes enables semiartificial photosynthesis for solar energy conversion. A key challenge is to achieve a uniform PSII distribution with efficient charge transfer. Here, we grow an inverse-opal CeO₂ (IO-CeO₂) scaffold directly on the electrode and utilize polyaniline (PANI) electrodeposition to facilitate PSII attachment. The PANI interlayer improves PSII loading and alignment on IO-CeO₂, broadens visible-light absorption, and establishes a Z-scheme/type-II tandem heterojunction, enhancing photogenerated electron transfer and resulting in a photocurrent of 5.9 ± 0.1 μA cm⁻² in a direct electron transfer system. A 9 cm² PSII-PANI2-IO-CeO₂ photoanode produces 12.3 ± 0.1 μmol of O₂ after 1000 min, which is a 76% increase compared to PANI2-IO-CeO₂. This approach offers simple design rules for efficient biointerface engineering that can be applied to other biohybrid systems.Junxian Gao, Yuqin Lu, Jingkai Lin, Wenjie Tian, Shaobin Wang, Huayang Zhan
Biomass Native Structure Into Functional Carbon-Based Catalysts for Fenton-Like Reactions
No full textOnlinePubl. Available online 10 June 2025Advancing biomass-derived carbon materials requires a systematic understanding of how distinct biomass structures influence their properties and functionality. To address this, eight 2D flaky and 1D acicular plant biomasses is systematically compared to synthesize pristine carbon, N-doped carbon, and cobalt/graphitic carbon for Fenton-like peroxymonosulfate (PMS) activation. Biomass pyrolysis under 5% NH(3) generates surface N-doped amorphous carbon, facilitating a selective electron transfer pathway (ETP), where highNincorporation, specific surface area, and atomic-level control overOgroups synergistically enhance its efficiency. While COOH groups contribute positively, excessive defects and C═O groups hinder ETP performance. Notably, compared to 2D biomass, 1D acicular biomass induces tubular carbon with lower C═O content, promoting the ETP regime. 2D flaky biomass facilitates Co nanoparticle incorporation in cobalt/graphitic carbon, where high contents of N, Co, defects, and oxygen groups (C═O/C─O/COOH) enhance sulfate radical (SO(4) (•)(−) )- dominated catalysis, whereas excessive sp2 C (>75–80 at.%) negatively affects performance. Through structural characterization, mechanistic analysis, and quantitative linear fitting correlations, this study identifies biomass-derived key active site interactions governing electron transfer and SO(4) (•)(−)-driven oxidation mechanisms. These insights establish a framework for sustainable, biomass-structure-driven carbon design for environmental catalysis.Wenjie Tian, Jingkai Lin, Zhihao Tian, Selusiwe Ncube, Huayang Zhang, Emiliano Cortés, Hongqi Sun, and Shaobin Wan
Kinetics and mechanism of synergistic adsorption and persulfate activation by N-doped porous carbon for antibiotics removals in single and binary solutions
No full textPorous carbon serves as a green material for efficient wastewater purification by adsorption and advanced oxidation processes. However, a clear understanding of the simultaneous removal of multiple pollutants in water is still ambiguous. Herein, the synergistic effect of adsorption and peroxydisulfate (PS) activation on kinetics and mechanism of removing single and binary antibiotic pollutants, sulfamethoxazole (SMX) and ibuprofen (IBP), from water by biomass-derived N-doped porous carbon was investigated. Our findings suggest that adsorption contributed to efficient removals of SMX/IBP. Comparative quenching experiments and electrochemical analysis demonstrated that hydroxyl (•OH) and sulfate (SO4•-) radicals, as well as singlet oxygen (1O2) led to the catalytic degradation of SMX, while only 1O2 reacted for IBP oxidation. Superoxide ion (O2•-) radicals were not related to SMX/IBP degradation. Electron transfer pathway accounted for PS activation but was not involved in direct SMX/IBP oxidation. Only slight differences were found between the degradation kinetics of SMX and IBP in the binary and single SMX or IBP solutions. This arose from the non-selective effect of adsorption and 1O2 attack for SMX/IBP removal, and the weak selective oxidation process of SMX by •OH and SO4•-. This study provides a new viewpoint on the role of adsorption in catalysis and enriches the mechanistic study of multi-component antibiotic degradation.Wenjie Tian, Jingkai Lin, Huayang Zhang, Xiaoguang Duan, Hao Wang,
Hongqi Sun, Shaobin Wan
Thiophene vs. benzene: how Pi-spacer engineering transforms photocatalytic hydrogen evolution
No full textConjugated porous polymers (CPPs) are promising materials for photocatalysis, yet their efficiency is highly dependent on the rational design of molecular frameworks. Here, we synthesized two donor–π–acceptor (D–π–A) type CPPs using spirobifluorene as the donor and triazine as the acceptor, introducing different π spacer units, benzene and thiophene, to investigate their effect on photocatalytic activity. The incorporation of thiophene as a π-spacer enhances electron delocalization within the triazine acceptor, effectively reducing charge transfer distance and improving the migration rate of photogenerated carriers. Theoretical calculations reveal that the thiophene-linked polymer (ThSF-CPP) exhibits a narrower bandgap, stronger intramolecular charge transfer, and a higher degree of electron localization at the active sites, facilitating efficient hydrogen evolution. Consequently, ThSF-CPP achieves a high hydrogen evolution rate (HER) of 16.75 mmol h‾¹ g‾¹ under full-arc irradiation, with an apparent quantum yield of 7.3% at 475 nm. Upon introducing 3 wt% Pt as a cocatalyst, the HER further increases to 34.65 mmol h‾¹ g‾¹. These findings underscore the crucial role of π-spacer engineering in optimizing charge separation and transfer, offering a molecular design strategy for high-performance polymer-based photocatalysts.Zibin Li, Xiujuan Zhong, Ya Chu, Jingkai Lin, Fanpeng Meng, Jinsheng Zhao, Zhengrong Wei, and Huayang Zhan
Identifying how future climate and land use/cover changes impact streamflow in Xinanjiang Basin, East China
No full textClimate and land use/cover changes are the main factors altering hydrological regimes. To understand the impacts of climate and land use/cover changes on streamflow within a specific catchment, it is essential to accurately quantify their changes given many possibilities. We propose an integrated framework to assess how individual and combined climate and land use/cover changes impact the streamflow of Xinanjiang Basin, in East China, in the future. Five bias-corrected and downscaled General Circulation Model (GCM) projections are used to indicate the inter-model uncertainties under three Representative Concentration Pathways (RCPs). Additionally, three land use/cover change scenarios representing a range of tradeoffs between ecological protection (EP) and urban development (UD) are projected by Cellular Automata - Markov (CA-Markov). The streamflow in 2021–2050 is then assessed using the calibrated Soil and Water Assessment Tool (SWAT) with 15 scenarios and 75 possibilities. Finally, the uncertainty and attribution of streamflow changes to climate and land use/cover changes at monthly and annual scale are analyzed. Results show that while both land use/cover change alone and combined changes project an increase in streamflow, there is a disagreement on the direction of streamflow change under climate change alone. Future streamflow may undergo a more blurred boundary between the flood and non-flood seasons, potentially easing the operation stress of Xinanjiang Reservoir for water supply or hydropower generation. We find that the impacts of climate and land use/cover changes on monthly mean streamflow are sensitive to the impermeable area (IA). The impacts of climate change are stronger than those induced by land use/cover change under EP (i.e., lower IA); and land use/cover change has a greater impact in case of UD (i.e., higher IA). However, changes in annual mean streamflow are mainly driven by land use/cover change, and climate change may decrease the influence attributed to land use/cover change.Accepted Author ManuscriptWater Resource
Photosystem II-Carbon Nitride Photoanodes for Scalable Biophotoelectrochemistry
No full textOnlinePubl.
Available online 15 August 2025Photosystem II (PSII) is a vital photosynthetic enzyme with the potential for sustainable bioelectricity and fuel generation. However, interfacing PSII with intricate, small-scale electrodes for practical applications has been challenging. This study addresses this by creating protonated macroporous carbon nitride (MCN) as support and developing a scalable spray-freeze method to wire PSII with MCN. This facilitates the production of large-area MCN-PSII photoanodes up to 33 cm² for biophotoelectrochemical water oxidation to O², achieving efficient interfacial charge transfer and initial photocurrents in the mA range with Faradaic yield of 93.5 ± 8.5% over 5 h. A bias-free biophotoelectrochemical (BPEC) device is designed by connecting the MCN-PSII photoanode to a carbon nanotube cathode loaded with bilirubin oxidase. An array of eight tandem BPEC cells with a photoactive area of 72 cm² successfully powers low-power electronics, such as LEDs. This work paves an efficient way for bioelectrode fabrication, showcasing the potential of PSII-based semi-artificial systems for BPEC and biophotovoltaic applications.Huayang Zhang, Wenjie Tian, Jingkai Lin, Peng Zhang, Guosheng Shao, Sai Kishore Ravi, Hongqi Sun, Emiliano Cortés, Virgil Andrei, and Shaobin Wan
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