Low temperature strategy for the synthesis of Ta3N5 and electrochemical deposition of Ag3PO4 to modify TiO2 as an advanced photoelectrocatalyst for oxygen evolution reactions

In this study, low temperature strategy for the synthesis of Ta3N5 and electrochemical deposition of Ag3PO4 to modify TiO2 nanorods were proposed to construct a heterogeneous structural system with enhanced interfacial charge transfer. Introduction of n-type Ta3N5 suitable for the reduction reaction and p-type Ag3PO4 suitable for the oxidation reaction pose effect on photoelectrochemical (PEC) performance of Ag3PO4/Ta3N5-TiO2. This provides important insights into PEC performance by testing the optical absorption, carrier concentration, band gap, photocurrent density and stability of Ag3PO4/Ta3N5-TiO2. Compared with the bare TiO2, Ag3PO4/Ta3N5-TiO2 with a bandgap of 1.89 eV enhances absorption on the red side of the visible light spectrum. The optimised Ag3PO4/Ta3N5-TiO2 photoelectrode with the uniform morphology exhibits an enhanced photocurrent density of 15.08 mA cm−2 at 1.88 V vs. reversible hydrogen electrode (RHE), with 8.7 times enhancement compared with bare TiO2 (1.55 mA cm−2). Both the PEC performance and stability of the Ag3PO4/Ta3N5-TiO2 photoanode could be enhanced by the decoration of Ag3PO4 nanoparticles and Ta3N5. In addition, the synthesis of Ta3N5 materials by hydrothermal methods under low temperature strategies can be used as a reference to guide the preparation of more efficient photoelectrodes.