Photocatalytic activity of PANI and g-C3N4 modified silver phosphate heterojunction catalysts for phenol

Photocatalysis is an effective approach for phenol degradation, and the crux of realizing this process lies in the photocatalytic material. Silver phosphate (Ag 3 PO 4 ) is a highly efficient and pollution-free photocatalytic material; however, it has a high recombination rate of photogenerated charge carriers. In this study, aiming at the deficiencies of Ag 3 PO 4 , a simple in-situ precipitation method was utilized to successfully prepare an Ag 3 PO 4 /PANI/g-C 3 N 4 photocatalyst with excellent visible-light photocatalytic performance. An analysis was carried out on the composition, morphology, structure, and optical properties of the prepared samples. Compared with the pure Ag 3 PO 4 , Ag 3 PO 4 /PANI, and Ag 3 PO 4 /g-C 3 N 4 composites, the Ag 3 PO 4 /PANI/g-C 3 N 4 composite demonstrated a remarkable improvement in the photocatalytic degradation of phenol under visible light. The Ag 3 PO 4 /PANI/g-C 3 N 4 photocatalyst, with a mass ratio of PANI, g-C 3 N 4 , and Ag 3 PO 4 of 1:10:50, exhibited superior phenol degradation capabilities under visible light, achieving complete degradation within 30   minutes, a total organic carbon (TOC) degradation efficiency of 88.7%, and enhanced stability compared to pure Ag 3 PO 4 after four cycles. This study presents, for the first time, the strategic combination of PANI and g-C 3 N 4 to synergistically enhance the photostability and activity of Ag 3 PO 4 . Experiments involving electron spin resonance (ESR) and free-radical capture revealed that the main active species are holes and superoxide radicals. The objective of this research is to introduce novel concepts and techniques for the application of photocatalytic materials in environmental pollution management.