Co–P–B catalyst thin films prepared by electroless and pulsed laser deposition for hydrogen generation by hydrolysis of alkaline sodium borohydride: A comparison

Abstract Co–P–B catalyst thin films have been synthesized on Ni-foam and glass substrate by using electroless deposition (ED) and pulsed laser deposition (PLD) respectively. The efficiency of these catalyst films was tested by catalytic hydrolysis of NaBH 4 for H 2 generation. While the chemically produced Co–P–B film on Ni-foam shows similar activity as that of their corresponding powder, the Co–P–B film deposited by PLD exhibits much superior H 2 generation rate as compared to Co–P–B powder. We attribute this increased efficiency to the special features of the Co–P–B films which are in the form of nanoparticle-assembled films, a peculiar characteristic of PLD films for appropriate choice of the pulse laser parameters. The surface nanoparticle-configuration increases the active surface area and also favors electronic exchange mechanisms to promote hydrolysis process for H 2 gas generation. The films deposited by using laser energy density of 3 J/cm 2 show the highest activity in connection to the best configuration of the ablated nanoparticles. Different numbers of Co–P–B layers were deposited on Ni-foam by ED and it was found that at least four layers are required for complete coverage of the foam to have the best activity.