Ultrathin veil-like SnO2 supported Co3O4 nanoparticles for direct borohydride fuel cell anode

In direct borohydride fuel cell (DBFC), there is a contradiction between catalytic activity and specific discharge capacity (SDC) owing to the dual catalytic effects of most anode catalysts on both borohydride oxidation reaction (BOR) and borohydride hydrolysis reaction (BHR). To overcome this problem, a facile method to fabricate an ultrathin tin dioxide (SnO 2 ) supported cobalt oxide (Co 3 O 4 ) composite material (u-SnO 2 /Co 3 O 4 ) as DBFC anode catalyst was developed. Both catalytic ability for BOR and specific discharge capacity of the DBFC using the u-SnO 2 /Co 3 O 4 (DBFC-u-SnO 2 /Co 3 O 4 ) with 5–10 nm thick two-dimensional (2D) SnO 2 were improved. The maximum power density (52.5 mW cm −2 ) and SDC (1380 mAh g −1 ) of DBFC-u-SnO 2 /Co 3 O 4 were respectively increased by 105% and 1740% in comparison with those of DBFC with Co 3 O 4 as anode catalyst (DBFC-Co 3 O 4 ). The u-SnO 2 /Co 3 O 4 has higher specific surface area, electron donation ability, and the rate of desorption of intermediate product (such as BH 3 OH − , H ads ) which may account for the excellent catalytic performance of u-SnO 2 /Co 3 O 4 for BOR.