ABSTRACT
The research for efficient and low-cost electrocatalysts for water splitting are essential for the exploitation and application of hydrogen energy. Transitional metal phosphides are considered as one of the most promising bifunctional water splitting electrocatalysts. Herein, we reported a facile two-step method (firstly hydrothermal preparation, then phosphorization under low temperature) to synthesize the bead-chain like nanoarrays of CoP supported on three dimensional Nickel foam (CoP/NF). The as-prepared CoP/NF could act as an efficient bifunctional catalyst for overall water splitting. The catalyst exhibited remarkable activity for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline media,delivering a current density of 10 mA/cm2at an overpotential of 281 mV for OER and 95 mV for HER, respectively. Efficient water splitting in alkaline system was realized by applying a two-electrode system with the CoP/NF acting as both the anode and cathode. The applied potential was 1.63 V to obtain the current density of 10 mA/cm2,and good stability was also testified.
ABSTRACT
Hydrogen evolution from water electrolysis is one of the effective ways to obtain clean hydrogen energy in the future. Pt-based materials are the efficient catalysts in hydrogen evolution reaction, but it is expensive, difficult to recycle, which impedes its application in the development of hydrogen energy and economy. Therefore, it is the key trend to develop efficient non-noble metal electrocatalysts with the aim of providing cost-competitive hydrogen energy. In this review, we highlighted the recent research efforts toward the synthesis of noble metal-free electrocatalysts for the hydrogen evolution reaction ( HER) , mainly focusing on nanomaterial catalysts supported on carbon fiber materials. We reviewed several important kinds of heterogeneous non-noble metal electrocatalysts, including sulfides, selenides, carbides, phosphides, and oxides. In the discussion, emphasis was given to the synthetic methods of these HER electrocatalysts, and the strategies for performance improvement. In addition, this paper also briefly summarized the application of carbon fiber material as substrate in the field of electroanalytical chemistry.