Surface roughening of nanoparticle-stacked porous NiCoO2@C microflakes arrays grown on Ni foam for enhanced hydrogen evolution activity

Abstract It is a huge challenge to design and develope a highly active and stable non-noble metal electrocatalyst for hydrogen evolution reaction (HER) in alkaline solution. Increasing the active sites and improving conductivity of catalysts are the effective ways to enhance the catalytic performance. Here, nanoparticle-stacked porous NiCoO 2 @C microflakes arrays grown on Ni foam (NiCoO 2 @C-NF) was synthesized through a simple high temperature heat treatment reaction of the corresponding NiCo 2 O 4 -NF. The nanoparticle-stacked porous microflakes arrays provide a large amount of exposed active sites. Thus, NiCoO 2 @C-NF with 0.072 g of glucose used for their preparation exhibits remarkable performance with −10 and −100 mA cm −2 for HER at overpotentials of −128 and −184 mV in 1.0 M NaOH solution, respectively. It is much better than that of NiCo 2 O 4 -NF (a η 10 of −221 mV and η 100 of −379 mV).