Synergetic enhancement of photocatalytic ammonia borane hydrolysis via localized surface plasmon resonance and metal-support interaction

Abstract

Ammonia borane (AB, NH₃BH₃) possesses a high hydrogen storage capacity, rendering it an ideal candidate among various hydrogen storage materials. Enhancing the optical performance and electron density at active sites represents an effective strategy for achieving high-efficiency hydrogen production via photocatalytic AB hydrolysis. This study utilized phosphorus-doped (P-doped) sea urchin-shaped titanium dioxide (TiO₂) as a support for loading copper‑cobalt (CuCo) bimetallic alloy nanoparticles, leading to the development of the Cu_0.5Co_0.5/P-TiO₂ photocatalyst for the hydrolysis of AB to generate hydrogen (H₂). At 298 K, the H₂ production rate under illumination was measured at 957 mL min⁻¹ g⁻¹, with a turnover frequency (TOF) of 28.23 min⁻¹ under light conditions, which is 1.45 times higher than that observed in darkness. Experimental characterization reveals that the superior photocatalytic activity can be attributed to the localized surface plasmon resonance (LSPR) effect of metallic Cu as well as the metal-support (Cu_0.5Co_0.5/P-TiO₂) interaction. The synergistic effect of these factors enhances optical performance, optimizes the electronic structure of the catalyst, and effectively modulates the electron density of the active site of Co. This work presents a straightforward approach for achieving low-cost and efficient catalytic hydrolysis of AB to produce H₂.