Abstract
? 2022 Elsevier B.V.Hydrogen production by electrocatalytic water splitting is one of the most promising ways to solve energy crisis and environmental pollution. In this work, we investigated the effect of Ce element on the catalytic activity of water oxidation and urea oxidation. Taking the N-Ni3S2 as an example, the N-Ce-Ni3S2 and N-Ni3S2 @Ce(OH)3 were firstly synthesized by doping Ce element into N-Ni3S2 and constructing the interface of N-Ni3S2 and Ce(OH)3. This N-Ni3S2 @Ce(OH)3 exhibits enhanced catalytic activity through the construction of heterogeneous interfaces, whether water oxidation (overpotential of 360 mV @ 50 mA cm?2) or urea oxidation (1.37 V @ 100 mA cm?2). A series of experiments show that the construction of heterogeneous interface greatly enhances the electron transfer rate of the N-Ni3S2 @Ce(OH)3 material, promotes the exposure of more active sites and improves the conductivity of the material. The density functional theory calculation also provides the water adsorption energy of the N-Ni3S2, N-Ce-Ni3S2 and N-Ni3S2 @Ce(OH)3 materials, and it is found that the N-Ni3S2 @Ce(OH)3 materials give optimal water adsorption energy compared with the N-Ni3S2 intrinsic materials. Experimental results and theoretical calculations show that the main reasons for the increase in activity are exposure of more active sites and higher electron transfer rate rather than stronger water adsorption energy.
NSTL
Elsevier