Cobalt Based Phosphide Nanoarrays:Syntheses And Electrocatalytic Performances For Overall Water Splitting

The development of active and cost-effective electrocatalysts which operate in the same electrolyte for water splitting,including oxygen evolution reaction(OER)and hydrogen evolution reaction(HER),is highly desirable but remains a grand challenge.Designing and synthesizing high-effect stable electrocatlaysts for HER and OER is always the goal of researchers in this field.Based on the problem of low-effect and unstable electrocatalytic performance of OER and HER bifunctional electrocatlaysts,we combine the doping effect by the non-noble metal ion and the unique one-dimensional nanowire/two-dimensional nanosheet heterostructure together to achieve high-effect and stable overall water splitting.Herein,we report a facile two-step method to synthesize Mn-doped CoP nanosheet/nanowire heterostructure array supported on nickel foam(denoted as 1D/2D Mn-CoP)as bifunctional electrocatalysts for overall water splitting.The as-prepared 1D/2D Mn-CoP heterostructure array,exhibiting remarkable catalytic activity towards HER,which only requires an overpotential of 42 mV to attain a current density of 10 mA/cm2,together with its small Tafel slope of 43 mV/dec and high stability,is one of the best non-noble materials described to date.Furthermore,The 1D/2D Mn-CoP also efficiently catalyzes the OER and shows activity superior to the benchmark catalyst IrO2.Therefore,we use 1D/2D Mn-CoP as both the cathode and anode to achieve overall water splitting(OWS)with an operating voltage as low as 1.58 V for jOWS = 10 mA/cm2 in 0.5 M H2SO4,which also outperforms the combination of IrO2 and Pt/C as state-of-art catalysts.These performances are enabled by the heterostructure array and Mn doping,bringing new opportunities for achieving high-efficiency and low-cost OWS electrocatalysts.