State-of-the-art progress in Ag3PO4-based photocatalysts: Rational design, regulation and perspective

•High-efficiency Ag3PO4-based photocatalysts are summarized.•Strategies to enhance the stability of Ag3PO4 photocatalyst are elaborated.•The mechanisms of various strategies to boost the photocatalytic activity of Ag3PO4 are highlighted. Photocatalysts had been extensively investigated for decades and had great potential to apply in energy production, environmental treatment, and chemical synthesis. The discovery of new types photocatalysts and new methods to regulate and control the performance of photocatalysts has driven the development of photocatalysis. Since the discovery of Ag3PO4 photocatalyst, it has attracted the researchers’ attention arising from the unique properties of semiconductor with ∼2.4 eV band-gap, relatively high light-absorption and the strong oxidative ability, together with prominently high quantum efficiency, as compared with the other counterparts. However, the low photostability originating from photoinduced reductive reaction in the bulk Ag3PO4 and discordant bandgap restrains its application. The design of Ag3PO4-based photocatalysts with optimized bandgap and surface properties as well as stability is of great importance. In this paper, with the comprehension of the structure and internal mechanism in hand, many ways to regulate the performance of Ag3PO4 in term of microstructure controlling, conventional materials (semiconductors, metals, and carbon materials) and novel materials (novel inorganic materials, MOFs, natural materials, and polymers) compositing, together with doping were reviewed. Moreover, we introduced multiple mechanisms of the composites that were put forward in recent years consisting of conductor composite, heterojunction, and Z-scheme and S-scheme heterojunctions. By concluding the prfoposed models among these regulation methods, we systematically discussed the advantages and disadvantages among these regulation methods. Besides, the deeper researches on the effects brought by the solution environment also were noticed. We focused on the applicability of Ag3PO4-based photocatalysts in many fields such as energy production, environmental purification, even in biological medicine. We conclude the perspective toward the future challenges in the field. It's believed that the researches and applications on Ag3PO4 may be accelerated with our perspective and conclusion.