Synergy of Visible-Light Responsive Photocatalytic Materials and Device Engineering for Energy and Environment: Minireview on Hydrogen Production and Water Decontamination

Accelerated advances in photocatalysis demand alignment with a well-defined Technology Readiness Levels (TRLs) roadmap to overcome bottlenecks and attain TRLs of 3 or beyond. This minireview highlights the key components for the development of device technology for photocatalytic hydrogen production, focusing on visible-light responsive catalysts and lab-scale setups. Two main aspects are critical discussed: modifications in semiconductor-based materials and progress in device engineering design. In the first section, the emphasis is on two specific energy materials: visible-light active carbon nitrides (CN) and the established benchmark titanium dioxide (TiO2). Examples of both CN and TiO2 modified by heteroatom doping, semiconductor heterojunction, metal Schottky junction, pre- and post-thermal treatments are showcased. Furthermore, Imogolite nanotubes are introduced as evolving 1D nanostructured nanoreactors for energetic photoelectrocatalysis.