Hexavalent chromium (Cr(VI)) is a prominent toxic metal with significant adverse human health effects. Photocatalytic reduction of Cr(VI) to less-toxic trivalent chromium (Cr(III)) is a promising method for removing Cr(VI) from aquatic environments. However, this technique often suffers from electron-hole recombination of semiconductors and poor reduction efficiency. The photoelectrocatalytic microbial fuel cell (Photo-MFC), which can use wastewater and light to recover electricity, has recently been proven to improve the separation of photocarriers of semiconductors and enhance cathodic reduction of pollutants. Here, the reduction of Cr(VI) was investigated in a Photo-MFC with a Pd-decorated p-type silicon nanowire (Pd/SiNW) photocathode and a bioanode under visible light. The Cr(VI) reduction efficiency reached 98.7% in 8 h under visible light, which was much higher than that under dark condition (56.2%) and open-circuit condition (19.4%). The enhanced Cr(VI) removal was mainly attributed to the synergistic effect of Pd/SiNW photocathode and bioanode. Cr(VI) reduction in the Photo-MFC fitted well with pseudo-first-order kinetics. The kinetics constants and reduction efficiencies of Cr(VI) decreased with the increase of pH, initial Cr(VI) concentration and external resistance. This work provides a promising alternative to mitigate Cr(VI) pollution in aquatic environments.
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http://dx.doi.org/10.1016/j.scitotenv.2018.05.271 | DOI Listing |
This work aimed at addressing the problem of hexavalent chromium pollution in the water environment, designing and preparing the Cu/CuO/NH-MIL-88B (Fe) heterojunction material with NH-MIL-88B (Fe) as the carrier, Cu/CuO was loaded on NH-MIL-88B (Fe) by light-assisted reduction. The loading of CuO effectively improves the visible light absorption capacity of the composite material. The SPR effect of Cu improves the separation and transfer of photogenerated carriers in the composite material.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Department of Occupational and Environmental Health, Xiangya School of Public Health, Central South University, Changsha, China. Electronic address:
Traditionally, abiotic factors such as pH, temperature, and initial Cr(VI) concentration have been undoubtedly recognized as the external driving forces that dramatically affect the microbial-mediated remediation of Cr(VI) pollutants. However, concentrating on whether and how the biological behaviors and metabolic activities drive the microbial-mediated Cr(VI) detoxification is a study-worthy but little-known issue. In this study, Leucobacter chromiireducens CD49 isolated from heavy-metal-contaminated soil was identified to tolerate 8000.
View Article and Find Full Text PDFInorg Chem
January 2025
Department of Environmental Science and Engineering, Fuzhou University, Minhou, Fujian 350108, China.
Environmental concerns are driving the development of eco-friendly and effective methods for contaminant monitoring and remediation. In this study, a lanthanide porphyrin-based MOF with dual fluorescence sensing and photocatalytic properties was synthesized and applied for the detection and combined removal of Cr(VI) and ciprofloxacin (CIP). Using different excitation wavelengths, the material exhibited selective detection of Cr(VI) via fluorescence quenching and CIP through fluorescence enhancement.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, China. Electronic address:
Heterointerface engineering is an effective strategy to design and construct high-performance photocatalysts. Herein, polyaniline (PANI) nanoparticles and ZnTi layered double hydroxide (ZnTi-LDH) nanosheets were integrated to form organic-inorganic heterostructure (PANI/LDH) via d-π electronic coupling using in-situ polymerization for photocatalytic oxidation/reduction towards tetracycline (TC) and Cr(VI). The photocatalytic activity was closely related to feed amount of aniline (Ani) in the polymerization process, which the abundant PANI nanoparticles were evenly distributed on the surface of ZnTi-LDH nanosheets at the proper Ani feed amount, and thus reinforced d-π electronic coupling at the organic-inorganic interfaces more efficiently.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Mechatronics Engineering Department, School of Automobile, Mechanical and Mechatronics, Manipal University Jaipur, India. Electronic address:
Herein, novel hollow ZnO and ZnO@SnInS core-shell nanorods (NRs) with controlled shell thickness were developed via a facile synthesis approach for the efficient photocatalytic remediation of organic as well inorganic water pollutants. The introduction of SnInS shell layer coating over ZnO enhances visible light absorption, efficient exciton-mediated direct charge transfer, and reduces the band gap of ZnO@SnInS core-shell nanorods. The ZnO@SnInS core-shell nanorods show efficient solar-light driven catalytic efficiency for the disintegration of industrial dye (orange G), degradation of tetracycline, and reduction of hazardous Cr (VI) ions in aquatic systems.
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