Synthesis of a Z-scheme photocatalyst (P-doped g-C3N4/Bi3+-doped Ag3PO4) and its photocatalytic performance

A Z-scheme heterojunction photocatalyst was prepared by combining P-doped carbon nitride (PCN) and Bi3+-doped silver phosphate (BPO). The prepared materials were systematically characterized by SEM, XRD, XPS, FT-IR and electrochemical tests. The photocatalytic performance was investigated under visible light irradiation with tetracycline as the model pollutant. The results revealed that doping phosphorus had a markedly impact on widening the light absorption of PCN by reducing its bandgap. Water and hydroxyl groups adsorbed on the BPO surface increased as a result of bismuth doping. Besides, the photocurrent responses of PCN and BOP were all higher than those of the un-doped ones. Especially, doping phosphorus made valence band of PCN move up, while conduction band of BPO went downwards due to bismuth doping. This facilitated formation of Z-scheme heterojunction between PCN and BPO. Consequently, the photocatalytic activity of BPO/PCN was further enhanced. The pseudo-first-order kinetics constant of tetracycline degradation for BPO/PCN was 62.7, 8.2, 1.9, and 1.3 times higher than that for g-C3N4, PCN, Ag3PO4, and BPO, respectively. Radical trapping experiments confirmed that .O2 and h+ were major reactive species. Additionally, with BPO/PCN as the anode of photocatalytic fuel cell, the performance on decontamination and electricity generation was significantly enhanced. (c) 2023 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.