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

Synthesis of ammonia from photocatalytic N 2 reduction is challenging due to the fast recombination of electron–hole pairs and the low selectivity of N 2 on catalysts. This can be addressed by creating heterojunctions to separate the photogenerated carriers adequately. In this regard, BW/g‐C 3 N 4 is synthesized and the weight percentage of g‐C 3 N 4 is varied. The best photocatalytic activity for N 2 reduction reaction (N 2 RR) is achieved with a ratio of BW/gC 3 N 4 in 3.5:2 ratio, deemed to be the optimized heterojunction. N 2 ‐temperature programmed desorption analysis shows outstanding chemisorption of N 2 adsorbed on the BW/g‐C 3 N 4 surface compared to pristine g‐C 3 N 4 and BW. Additionally, forming a heterojunction enhances the charge transfer process and well‐separated electron–hole pairs, significantly boosting the water oxidation process on the catalytic surface. Photoelectrochemical analysis reveals that BW/g‐C 3 N 4 exhibits the shortest hole relaxation lifetime and higher current density than its pristine counterparts. The robust contact between g‐C 3 N 4 and BW reduces the work function of BW/g‐C 3 N 4 based on ultraviolet photoelectron spectroscopy data. Ammonia production with the optimized BW/gC 3 N 4 ‐3.5:2 is 5.3 and 2.1 times higher than pure g‐C 3 N 4 and Bi 2 WO 6 , respectively. Meanwhile, BW/g‐C 3 N 4 demonstrates excellent photocatalytic activity toward antibiotic pollutant degradation as well. After 150 min of visible light irradiation, the removal of 94% ciprofloxacin (CIP) is observed. Finally, a possible mechanism is proposed for photocatalytic N 2 RR and CIP degradation.