CoWO4/CoP2 nanoflakes grown on carbon nanotube film as an efficient electrocatalyst for water splitting in alkaline media

Abstract Tremendous efforts have been investigated in enhancing the catalytic activity of 3d-transition metal based materials (especially cobalt-based catalysts), which are regarded as promising candidates for non-noble catalysts in electrocatalytic water splitting. Herein, a facile one-step hydrothermal method is utilized to fabricate CoWO4/CoP2 nanoflakes (CTCP) on carbon nanotube film (CNTF), which constructs self-supported CTCP/CNTF composite electrocatalyst for water splitting. Benefitting from the well-configured structure, CTCP/CNTF possesses more active sites for reactions along with quicker interfacial charge transfer and better electrical conductivity. Meanwhile, embedding CoP2 in CoWO4 yields obvious synergistic effect to improve the intrinsic catalytic activity for OER and HER. In 1.0 M KOH, the optimized CTCP/CNTF-3 electrode requires a low overpotential of 252 mV at 10 mA cm-2 (anodic current density) for OER, and 133 mV at -10 mA cm-2 (cathodic current density) for HER. When employing CTCP/CNTF as both anode and cathode, the cell voltage for overall water splitting is only 1.605 V at jcell =10 mA cm-2, which value is extremely close to that of Pt/C/CNTF (-) // RuO2/CNTF (+). Remarkably, the electrolyzer (CTCP/CNTF(-) // CTCP/CNTF(+)) shows better stability for water splitting than Pt/C/CNTF (-) // RuO2/CNTF (+) over a duration of 32h at jcell =10 mA cm-2.