A Novel Earth-Abundant W-WC Heterojunction as Efficient Co-Catalyst for Enhanced Photocatalytic H2 Evolution

New functional materials are of significance for the industry development of coal and tungsten. Here, we reported a novel earth-abundant W-WC heterojunction on CdS as an efficient and cheap co-catalyst for photocatalytic H-2 evolution on CdS under visible light irradiation. The W-WC is simply synthesized from industrial raw material of coal and ammonium tungstate by a simple one-step calcination strategy. The photocatalytic activities tests show that W-WC heterojunction has better co-catalytic performance than W or WC alone, and the optimal photocatalytic activity of W-WC/CdS reaches 3314 mu mol/h/g, which are17.4 and 2.6 times larger than that of CdS and Pt/CdS alone, respectively. Electrochemical tests demonstrate the WC has large specific capacitance and acts as electron reservoir storing the photo-excited electron from CdS, whereas W mainly acts as the catalytic center. The heterojunction formed between W and WC is favorable for the electron transferring. The different functions of W and WC along with the heterojunction between W and WC account for the superiority of W-WC. The design and fabrication strategy of the W-WC heterojunction co-catalyst benefits for the industrial development of new material and photocatalysis.