Photocatalytic H₂ production from water splitting employing depolymerized cellulose through LiCl activation as sacrificial agent

We report a facile approach of depolymerizing cellulosic biomass by a physical pressing intensified inorganic salt hydrolysis (PIISH) process, in which inorganic ion (e.g. Li⁺) as an activation agent can be drilled into the outlayers of cellulose particles so as to break down the hydrogen bonds in cellulose, and the fragments detached from bulk cellulose could be further converted to glucose or other soluble carbohydrates by in situ formed LiOH or HCl catalyzed hydrolysis. The particle size, morphology and surface structure of microcrystalline cellulose are markedly changed which have been observed by a series of physicochemical characterization of PIISH treated cellulose. The cellulose depolymerization was related to the applied pressure and the type of inorganic ions, and about 4.5% cellulose was converted into glucose using LiCl salt at 20–30 MPa pressing. Platinized TiO₂ prepared by different approaches has been characterized and screened for photocatalytic H₂ production utilizing the cellulose decomposed products as sacrificial agents under UV light irradiation. The apparent quantum efficiencies in 5 h and 35 h for H₂ production under 365 ± 10 nm irradiation are about 6.12% and 2.36%. This facile approach has been applied for depolymerizing cellulosic biomass resources for solar driven H₂ production.