Facile synthesis of porous Cu2O hollow nanospheres for accelerating electroreduction of CO2 towards C2 products

•The porous Cu2O-HNSs were facilely prepared through a one-pot wet-chemical method.•The concentration of NH2OH∙HCl and pH value play critical roles in the synthesis.•Compared to Cu powder, Cu2O-HNSs showed an enhanced CER performance for C2 products.•The type of electrode and carbon support can impact the CER performance of Cu2O-HNSs.