Fabrication of modified g-C 3 N 4 nanorod/Ag 3 PO 4 nanocomposites for solar-driven photocatalytic oxygen evolution from water splitting

Abstract Semiconductor-based photocatalysis has been considered as one of the most effective techniques to achieve the conversion of clean and sustainable sunlight to solar fuel, in which the construction of novel solar-driven photocatalytic systems is the key point. Here, we report initially the synthesis of modified graphitic carbon nitride (g-C 3 N 4 ) nanorods via the calcination of intermediates obtained from the co-polymerization of precursors, and the in-situ hybridization of Ag 3 PO 4 with as-prepared modified g-C 3 N 4 to produce g-C 3 N 4 nanorod/Ag 3 PO 4 composite materials. The diameter of modified rod-like g-C 3 N 4 materials is determined to be around 1 μm. Subsequently the morphological features, crystal and chemical structures of the assembled g-C 3 N 4 nanorod/Ag 3 PO 4 composites were systematically investigated by SEM, XRD, XPS, UV–vis diffuse reflectance spectra (DRS). Furthermore, the use of as-prepared composite materials as the catalyst for photocatalytic oxygen evolution from water splitting was studied. The oxygen-generating results showed that the composite photocatalyst modified with 600 mg rod-like g-C 3 N 4 demonstrates 2.5 times higher efficiency than that of bulk Ag 3 PO 4 . The mechanism behind the enhancement in the oxygen-evolving activity is proposed on the basis of in-situ electron spin resonance (ESR) measurement as well as theoretical analysis. The study provides new insights into the design and development of new photocatalytic composite materials for energy and environmental applications.