Enhanced hydrogen production from ammonia borane over CuNi alloy nanoparticles supported on TiO2(B)/anatase mixed-phase nanofibers with high specific surface area

TiO2 with monoclinic phase (TiO2(B)) and anatase phase composite (TiO2 (B)/anatase) loaded with 3.66 wt% CuNi alloy nanoparticles (NPs) used as photocatalyst for the hydrolysis of ammonia borane (NH3BH3, AB). TiO2(B)/anatase mixed-phase is synthesized by calcination of the hydrothermally prepared titanic acid precursor. Then, the metal nanoparticles are loaded by an ammoniacal metal complex ion impregnation reduction method. The experimental results show that TiO2 generated by calcination at 700 degrees C (T700) consists of 77.73% anatase and 22.27% TiO2(B) while displaying a specific surface area of 205.5 m(2) g(-1). The as-synthesized Cu0.36Ni0.64-T700 catalysts displayed the highest H-2 production rate of 8131.15 mL/(g.min) with a total turnover frequency (TOF) of 21.87 mol(H2)/(mol(metal) min) for the dehydrogenation of AB. These results are rationalized in terms of one-dimensional character of fiber and high specific surface area, which provided a higher number of surface-active sites for the photocatalytic reaction. In addition, the electronic and structural properties of TiO2(B) and anatase phases found in the support are benefit for the separation of electrons and holes in the catalytic process. It can be affirmed that this study provides a cost-effective and efficient method for improving the photocatalytic activity of various metal-TiO2 heterojunction photocatalysts. (C) 2019 Elsevier B.V. All rights reserved.