A novel in situ microwave-assisted biomimetic route to modified TiO2 photocatalysts for efficient hydrogen generation under solar irradiation

Hydrogen (H 2 ) is widely recognized as a clean and sustainable energy carrier, capable of supporting the global transition toward carbon-neutral energy systems. Among the various production strategies, photocatalytic hydrogen generation from aqueous media using solar energy stands out as a green and low-impact alternative to conventional reforming methods. In particular, the photoreforming of organic compounds, such as alcohols, has emerged as an attractive approach, enabling both H 2 production and the valorization of organic substrates. In this work, a series of TiO 2 -based photocatalysts were synthesized through a novel in situ microwave-assisted biomimetic method, incorporating a marine sponge as a bio-template to modulate the textural and chemical properties of the materials. Several sponge-containing composites (TiO 2 _Sx) were prepared and characterized, with platinum added as a cocatalyst to promote charge separation and enhance H 2 evolution activity. The photocatalytic performance of the materials was evaluated under simulated solar light using four alcohols, methanol, ethanol, ethylene glycol, and 1,2-propanediol, as sacrificial agents. Among the tested photocatalysts, the TiO 2 _S5 sample exhibited the highest H 2 production rate. Ethylene glycol was identified as the most effective sacrificial agent, yielding a maximum H 2 generation rate of 1196 μmol·g cat −1 ·h −1 and concurrent CO 2 evolution of 1156 μmol·g cat −1 ·h −1 , indicating efficient photoreforming. The superior performance of ethylene glycol is attributed to its vicinal diol structure, which promotes effective hole scavenging. These findings demonstrate that the combination of sponge-assisted TiO 2 structuring and polyhydric alcohols as sacrificial agents provides a promising platform for improving solar-driven H 2 production through photoreforming. • Microwave-assisted in-situ biomimetic route rapidly yields crystalline TiO 2 . • Biotemplating increases surface area and porosity without lattice distortion. • Microwave-assisted sponge-templated TiO 2 boosts solar H 2 evolution efficiency. • Optimal TiO 2 _S5 delivers 1196 μmol H 2 g −1 h −1 under simulated sunlight. • H 2 and CO 2 generated simultaneously, evidencing efficient photoreforming.