Work

Spatially decoupled Janus membrane with Z-scheme Ag/BiOBr@MIL-53(Fe) heterojunction for enhanced solar-driven interfacial photocatalysis and Cr(VI) remediation: A proof-of-concept laboratory study for model dye degradation and Cr(VI) reduction under simulated solar irradiation

Year: 2026

Type: article

Abstract: The remediation of persistent organic dyes and hexavalent chromium (Cr(VI)) in industrial wastewater remains challenging because these pollutants require different redox processes and efficient charge separation. Herein, we introduce a rationally designed, self-floating Janus membrane, Ag/BiOBr@MIL-53(Fe)@CF/SS, as a proof-of-concept platform for solar-driven interfacial photocatalysis. The membrane integrates a superhydrophilic stainless-steel (SS) layer, which promotes rapid capillary-driven pollutant transport, with a hydrophobic and conductive carbon-fiber (CF) support that facilitates directional electron migration. Discontinuous Ag nanoparticles were introduced into the BiOBr@MIL-53(FE) framework by 2s magnetron sputtering, providing plasmonic active sites without forming a continuous metallic layer. The observed band-alignment and charge-transfer behavior are consistent with a Z-scheme-type charge-transfer pathway, although alternative pathways (e.g., type-II with Schottky trapping) cannot be excluded based on the present data. In separate single-component model pollutants under simulated solar irradiation, the membrane achieved 99% Rhodamine B removal within 60 min, with a rate constant of k = 4.5 × 10 −2 min −1 , and complete Cr(VI) reduction within 165 min, with a rate constant of k = 1.6 × 10 −2 min −1 . Dark adsorption removed 49% of Rhodamine B and 31% of Cr(VI), demonstrating a pre-concentration effect that accelerated subsequent photocatalytic reactions. Mechanistic studies indicated electron-dominated Cr(VI) reduction and synergistic adsorption-oxidation of Rhodamine B. Further studies under continuous floating operation and real wastewater conditions are required.

Source: Materials Science in Semiconductor Processing

DOI: 10.1016/j.mssp.2026.111154

Authors: Temesgen Takele Niguso, Chang-Mou Wu, Kebena Gebeyehu Motora, Jinn P. Chu, Jhih-Yu Tsai, Pankaj Koinkar

Institutions: National Taiwan University of Science and Technology, Tokushima University

Language: English

Topic: Advanced Photocatalysis Techniques

Subfield: Renewable Energy, Sustainability and the Environment

Field: Energy

Domain: Physical Sciences

SDG: Clean water and sanitation

Open Access status: hybrid

Estimated APC paid: $3,540