Halloysite nanotubes supported Co₂P bridged by carbon dots for enhanced hydrogen evolution from ammonia borane

Rational design of efficient, low-cost and eco-friendly catalysts for hydrogen generation from solid-state hydrogen storage material ammonia borane (AB) is identified as an ideal approach for solving the problems of energy crisis and environmental pollution. Herein, we construct a robust and low-cost composite catalyst with the combination of non-noble metal cobalt phosphide (Co2P), carbon dots (CDs) and halloysite nanotubes (HNTs), in which CDs serve as the bridge and conductive mediator to link Co2P and HNTs for facilitating electron transfer. Attributing to the synergistic effects among Co2P, CDs and HNTs, the high conductivity of CDs and the dispersion/supporting of HNTs, the as-prepared Co2P-CDs/mHNTs composite catalyst displays a considerably high hydrogen evolution rate with TOF of 178.02 mol(H2) mol(co2P)(-1) min(-1), which is much higher than Co2P/HNTs, Co2P/CDs and other non-noble metals-based catalysts. This work provides a new insight and bridging strategy for the design of low-cost composite catalysts with excellent performance toward AB hydrolysis.