Optimizing photocatalytic water oxidation by FeMnO_x bimetallic cocatalyst on Zn-doped BiVO₄ via magnetron sputter deposition

Author(s)

Khan, Niqab ; Koche, Ariadne ; Khan, Wahidullah ; Nogueira, Pallas A. M. ; Jamil, Asif ; Pieper, Yvonne ; Toma, Francesca M. ; Nascimento, Otaciro R. ; Goncalves, Renato V. ; Khan, Sherdil

• Document type: Journal article
• Source: APPLIED CATALYSIS A-GENERAL; v. 704, p. 10-pg., 2025-08-25.

Abstract

Bismuth vanadate (BiVO4) has been used as an efficient photocatalyst for water oxidation. However, pristine BiVO4 suffers from recombination due to its short hole diffusion length and fast electron-hole recombination, which hinders photocatalytic water oxidation. To enhance the water photo-oxidation, here we constructed Zndoped BiVO4 and then deposited bimetallic FeMnOx on its surface via Magnetron Sputtering. Zn doping improved the optical absorption by red-shifting the bandgap of BiVO4. Crystalloghafically, it increased growth towards (040) direction and enhanced V-O bond lengths. Moreover, the Zn doping induces oxygen vacancies that suppress charge recombination, as confirmed by EPR analysis. Zn-doped BiVO4 showed an incredible enhancement in the photocatalytic O2 evolution of 135 mu mol as compared to the pure BiVO4 (90 mu mol). The O2 evolution was further enhanced to 154 mu mol after loading bimetallic FeMnOx cocatalysts on Zn-doped BiVO4, which is attributed to the improved charge transportation via cocatalysts from the BiVO4 surface. (AU)

• FAPESP's process: 23/15633-0 - Development of BiVO4-based hyperfine heterojunctions for photoelectrochemical reactions
• Grantee: Niqab Khan
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 14/50279-4 - Brasil Research Centre for Gas Innovation
• Grantee: Julio Romano Meneghini
• Support Opportunities: Research Grants - Research Centers in Engineering Program
• FAPESP's process: 20/15230-5 - Research Centre for Greenhouse Gas Innovation - RCG2I
• Grantee: Julio Romano Meneghini
• Support Opportunities: Research Grants - Research Centers in Engineering Program
• FAPESP's process: 23/00618-6 - Development of Semiconductor Devices for Green Hydrogen Production via Photoelectrochemical Water Splitting without External Polarization
• Grantee: Renato Vitalino Gonçalves
• Support Opportunities: Research Program on Global Climate Change - Regular Grants