Bi₂WO₆ Incorporation of g‐C₃N₄ to Enhance the Photocatalytic N₂ Reduction Reaction and Antibiotic Pollutants Removal

Abstract

Synthesis of ammonia from photocatalytic N2 reduction is challenging due to the fast recombination of electron‐hole pairs and the low selectivity of N2 on catalysts. This can be addressed by creating heterojunctions to separate the photogenerated carriers adequately. In this regard, we synthesized BW/g‐C3N4 and varied the weight percentage of g‐C3N4. The best photocatalytic activity for N2 reduction reaction (N2RR) was achieved with a ratio of BW/gC3N4 in 3.5:2 ratio, deemed to be the optimized heterojunction. N2‐temperature programmed desorption analysis showed outstanding chemisorption of N2 adsorbed on the BW/g‐C3N4 surface compared to pristine g‐C3N4 and BW. Additionally, forming a heterojunction enhanced the charge transfer process and well‐separated electron‐hole pairs, significantly boosting the water oxidation process on the catalytic surface. Photoelectrochemical analysis revealed that BW/g‐C3N4 exhibits the shortest hole relaxation lifetime and higher current density than its pristine counterparts. The robust contact between g‐C3N4 and BW reduced the work function of BW/g‐C3N4 based on ultraviolet photoelectron spectroscopy data. Ammonia production with the optimized BW/gC3N4 3.5:2 was 5.3 and 2.1 times higher than pure g‐C3N4 and Bi2WO6, respectively. Meanwhile, BW/g‐C3N4 demonstrates excellent photocatalytic activity towards antibiotic pollutant degradation as well. After 150 minutes of visible light irradiation, the removal of 94% ciprofloxacin (CIP) was observed. Finally, a possible mechanism is proposed for photocatalytic N2RR and CIP degradation.TOC: The distinctive feature of the Bi2WO6/g‐C3N4 hybrid is its innovative combination of Bi2WO6/g‐C3N4, creating a specialized interface that maximizes visible light absorption, enhances charge separation, and facilitates both N2 reduction reaction and pollutant degradation, and making a promising material for sustainable environmental application.This article is protected by copyright. All rights reserved.