Abstract
Co-B nanoflakes-like structure supported over nanoporous TiO2 nanofibers (Co-B NFls-TiO2 NFs, nanocatalyst) was synthesized in two steps using electrospinning technique and chemical reduction method. Nanoporous TiO2 NFs were prepared by calcination of electrospun sol-gel consisting of titanium tetraisopropoxide (TIIP) and polyvinylpyrrolidone (PVP). Then, Co-B NFls were supported over TiO2 NFs by chemical reduction of cobalt acetate tetrahydrate (CoAc) over TiO2 NFs using sodium borohydride (NaBH4) as a reducing agent. The nanocatalyst was used for hydrogen generation from environmentally safe and non-toxic ammonia borane (AB). TEM and FESEM results revealed that NFls were well supported on the surface of nanoporous TiO2 NFs. The supported NFs helped in precluding Co-B agglomeration, however; the unsupported NFs suffered from agglomeration due to harsh reaction created during hydrogen generation. As the synthesized nanocatalyst showed superior catalytic activity in AB hydrolysis compared to that of Co-B powder. The hydrogen evolution was approximately 2.85 mol in 8 min and 0.7 mol in 22 min using nanocatalyst and Co-B powder, respectively. Furthermore, the synthesized nanocatalyst showed low effective activation energy, E-a similar to 16.54 kJ/mol and high maximum rate similar to 2745.6 ml g(-1) min(-1). Finally, the main features of the prepared nanocatalyst were highly efficient, economical, and recyclable. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.