Photoinduced electron-rich CuNi@C/TiO2 catalyst for highly efficient hydrogen production from formaldehyde aqueous solution

Catalytic conversion efficiency from aqueous formaldehyde (HCHO) into hydrogen (H 2 ) on non-noble metal catalysts is much lower than that on noble metal catalysts. Modulating the electronic properties of non-noble metal-based catalysts has been demonstrated an effective approach to improve their catalytic performance. In this work, assisted by light irradiation, photoinduced electron-rich surface structure was designed for the thermal catalytic conversion of HCHO to H 2 . In detail, a heterostructure of CuNi@C composited with TiO 2 was obtained, in which TiO 2 can be photoexcited under light irradiation to provide photoinduced electrons onto the surface of CuNi@C. On the photoinduced electron-rich surface of the CuNi@C/TiO 2 heterostructure, the H 2 evolution rate reached 254.65 mmol h −1 g −1 , which was 1.88 times higher than that on CuNi@C. It is worth noting that the catalytic HCHO conversion efficiency outperforms the current reported non-noble metal catalysts for this reaction. Combining with density functional theory (DFT) calculations and experimental studies, it is concluded that the electron-rich CuNi@C dramatically reduced the activation energies of the dissociation of HCHO and H 2 O and accelerated the overall reaction rate.