Sub-10 nm anatase TiO2 nanoparticles for rapid photocatalytic H2 production from lignocellulosic biomass

Abstract

Photocatalytic H₂ production from lignocellulosic biomass represents an ideal conversion path for the green utilization of lignocellulosic biomass as an energy resource, but the lack of efficient photocatalysts resulted in poor H₂ production activity for photocatalytic lignocellulosic biomass-to-H₂ conversion. The achievement of high photocatalytic H₂ production activity is primarily limited by the low ˙OH generation rate resulting from the limited active sites related to the small specific surface, and partly restricted by the slow kinetics of H₂ generation reaction. Herein, we design and prepare sub-10 nm anatase TiO₂ nanoparticles as high-reactive photocatalysts for photocatalytic lignocellulosic biomass-to H₂ conversion by using Pt nanoclusters (Pt NCs) as the cocatalyst. Owing to the abundant active sites for ˙OH generation resulting from the large specific surface of sub-10 nm TiO₂ and the fast H₂ generation kinetics of Pt NCs, the optimal Pt NCs/TiO₂ shows a high photocatalytic H₂ production activity in cellulose solution with the highest H₂ generation rate of 540 μmol h⁻¹ g⁻¹ and an apparent quantum yield of 4.1% at 380 nm. Furthermore, the H₂ generation rate of the optimized Pt NCs/TiO₂ photocatalyst achieves 2, 6, 25, 39, 10 and 2 μmol h⁻¹ g⁻¹ in rice straw, corncob, polar wood chip, bamboo, rice hull and wheat straw aqueous solution, respectively. This study provides new insight into the design of highly-efficient photocatalysts for photocatalytic lignocellulosic biomass-to-H₂ conversion systems.