Enhanced electrocatalytic water splitting activity by using Ni0.85Se anchored on amorphous Ni4Mo alloy

To design and construct bifunctional electrocatalyst with high activity is important to the commercial development of electrochemical water splitting (EWS) technology. The carbon clothe (CC) supported on Ni(OH)2 nanosheet is used as template to tune the morphology of Ni0.85Se. To improve the activity of Ni0.85Se, amorphous Ni4Mo alloy is anchored on the Ni0.85Se to obtain the Ni0.85Se/Ni4Mo catalyst (NS/NM) by electrodeposition method. The electron state and conductivity of NS/NM are modulated compared to that of the NS sample. It is found that the electron transfers from Ni4Mo to Ni0.85Se. Benefiting from the tuned electron state of Ni0.85Se and Ni4Mo, the enhanced number of exposed active sites and lower Rct value, the NS/NM heterostructure electrode requires low overpotentials of 51 and 206 mV to obtain 10 mA cm−2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The optimized electrode shows fast kinetics and exhibits near to 100% Faraday efficiency for HER and OER in 1 M KOH. Importantly, it is noted that the electrocatalytic activity of NS/NM catalyst for both HER and OER is enhanced obviously in comparison with NS sample. With heterostructure catalyst, the EWS only proceeds at 1.48 V to yield 10 mA cm−2, which is reduced about 110 mV compared to NS electrode. Here, a novel kind of bifunctional heterostructure electrocatalyst is constructed.