1. Synchronous generation of H2O2 and high effective removal of inorganic arsenic/organoarsenic by visible light-driven cell.
- Author
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Sun, Yan and Zhang, Lei
- Subjects
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ARSENIC removal (Water purification) , *PHOTOCATHODES , *POLYTEF , *POLLUTION remediation , *IRON , *ENERGY consumption , *ARSENIC - Abstract
A Janus photocathode of asymmetric wettability with hydrophobic oxygen storage layer and hydrophilic catalyst layer was successfully fabricated by graphite felt (GF) polytetrafluoroethylene (PTFE)-hydrophobization and a subsequent hollow sphere NiFe 2 O 4 @ZnFe 2 O 4 (NF@ZF) Z-scheme photocatalysts coating on the other side of GF. The designed Janus electrode showed significantly higher H 2 O 2 production than hydrophilic (NF@ZF/GF) and hydrophobic (NF@ZF/PTFE/GF) electrodes, and achieved a higher faradaic efficiency of 72%, as well as a record H 2 O 2 production rate of 255.9 mg·L−1∙h−1, while maintaining a stable photoelectrochemical performance for 9 h at 2.8 mA∙cm−2 in Na 2 SO 4 solution. The two-electrode co-photoelectrolysis system by coupling the ORR with inorganic arsenic/organoarsenic oxidation can simultaneously produce H 2 O 2 at Janus photocathode and As (V) at Fe anode under a low energy consumption (a cell voltage of only 0.7 V), respectively, and then the generated As (V) could be rapidly removed (above 93%) by adsorption onto Fe (III) (hydro)oxides. [Display omitted] • Novel architecture of NiFe 2 O 4 @ZnFe 2 O 4 electrode with tunable wettability is proposed. • Designed Janus photoelectrode shows highly H 2 O 2 yield and low energy consumption. • Janus electrode mitigated the O 2 mass transport and adequate ion transport limitation. • Clever build Janus ‖ Fe cell in-situ Fenton achieves arsenic pollution remediation. • Generated low toxic arenates can be simultaneously immobilized on iron (hydro)oxide. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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