Heterojunction of CuMn2O4/CeO2 nanocomposites for promoted photocatalytic H2 evolution under visible light

It is significant to design a photocatalyst with highly efficient H2 evolution utilizing solar energy to be a renewable energy sources. Heterojunction CuMn2O4/CeO2 nanocomposites were constructed by a facile sol–gel approach utilizing a nonionic surfactant. The H2 evolution of the heterojunction CuMn2O4/CeO2 photocatalysts compared with pure CeO2 NPs was addressed under visible light. Glycerol was employed as an electron donor, and Pt NPs were in-situ photo-reduced during the reaction onto the CuMn2O4/CeO2 surface. The TEM and XRD results verified the build of CuMn2O4/CeO2 nanocomposites with cubic phases of CeO2 and CuMn2O4 and particles size of about 10 nm. The results indicated that the H2 evolution of 15%CuMn2O4/CeO2 photocatalyst was determined at about 23,650 μmol·g−1 after being illuminated for 9 h, while that of pure CeO2 was 4774 μmol·g−1. The H2 evolution rate of 15%CuMn2O4/CeO2 photocatalyst was enhanced five times larger than pure CeO2. The enhanced H2 evolution rate over the synthesized CuMn2O4/CeO2 nanocomposites can be attributed to the effective electron transport ability, enhancement of the separation efficiency of electrons–hole. The construction of CuMn2O4/CeO2 S-scheme heterojunction is advantages to minimize the recombination of electron–hole, boosting the carriers lifetime, and enhancing the photocatalytic ability. The mechanism of photocatalytic H2 evolution over CuMn2O4/CeO2 photocatalyst is illustrated. This study provides an effective and simple procedure to perform a reasonably constructed photocatalyst for cost-effective, stabilized and efficient solar H2 evolution applications.