Efficient Synthesis of Ag–Co3O4 Nanocatalysts for Hydrogen Evolution from Ammonia Borane Hydrolysis

— It is of great significance to prepare high-performance non-precious metal catalysts for hydrogen evolution from the ammonia borane (NH 3 BH 3 , AB). Here, a series of cost-effective and high-performing Ag–Co 3 O 4 nanocatalysts were prepared using AgNO 3 and Co(NO 3 ) 2 ⋅6H 2 O as precursors. The influence of varying doping amounts of Ag atoms (10 mg AgNO 3 , 20 mg AgNO 3 , 40 mg AgNO 3 , 60 mg AgNO 3 ) and heat treatment temperatures (300, 400, 500, 600°C) on the catalytic activity of the Ag–Co 3 O 4 nanocatalysts for AB hydrolysis was investigated. The obtained results reveal that the Ag–Co 3 O 4 nanocatalysts exhibit a well-defined nano-flower morphology with homogeneous distribution of silver atoms over the Co 3 O 4 surface. Moreover, an evident electronic synergy between Ag and Co 3 O 4 is observed. The 20-Ag–Co-500 catalyst (doped with 20 mg of AgNO 3 and subjected to heat treatment at 500°C) exhibits exceptional catalytic activity towards AB hydrolysis (TOF = 348.03 \({\text{mo}}{{{\text{l}}}_{{{{{\text{H}}}_{{\text{2}}}}}}}\) min –1 \({\text{mol}}_{{{\text{Ag}}}}^{{ - 1}}\) and E a = 56.20 kJ/mol).