Thermo-Photocatalysis: Environmental and Energy Applications

Waste-derived Materials: Opportunities in Photocatalysis

Waste-derived materials have been gaining increased attention in recent years due to their great potential and environmentally friendly nature. Several contributions in the literature have covered the advances achieved so far in this area. Nonetheless, to the best of our knowledge, no review has been dedicated specifically to waste-derived or templated photocatalytic materials. Both photocatalysis and (bio)waste-inspired design yield materials of a remarkably green nature. Therefore, the partnership between them may open promising possibilities for both waste valorization and photocatalytic processes, which in turn will lead to sustainable development globally, with the potential for full utilization of renewable energy sources such as biomass and sunlight. Several photocatalytic waste-derived materials, synthetic procedures, and applications will be described throughout this work, including waste-derived/templated TiO₂, ZnO, and metal sulfide materials. Special attention will be given to biomass-inspired carbonaceous materials, including carbon quantum dots and graphitic carbon nitride (g-C₃N₄).

Modulation of oxygen vacancy in tungsten oxide nanosheets for Vis-NIR light-enhanced electrocatalytic hydrogen production and anticancer photothermal therapy

Oxygen vacancy (OV) tuning was introduced into oxygen-deficient WO3 nanosheets to optimize the chemical and electronic properties. Enhanced electronic conduction, extended light absorption, enhanced HER reaction kinetics and benign photothermal performance were verified by density functional theory (DFT) calculations and experimental studies. Vis-NIR light-enhanced electrocatalytic HER was accomplished with a small overpotential of 52 mV (at 10 mA cm-2) and a low Tafel slope of 37 mV dec-1 and performed much more efficiently than that in darkness, comparable to the noble-metal catalysts (Pt, Pt/C). Moreover, the resultant WO3-OVs possess good photothermal conversion efficiency. The promising potential of the WO3-OVs for anticancer photothermal therapy has been demonstrated with a high photothermal conversion efficiency (∼41.6%) upon single wavelength near-infrared irradiation and an efficient tumor inhibition rate (∼96.8%). This design of photoelectronic/thermal materials paves an exciting new avenue for the conversion of well-developed metal oxides to be high-performance and multifunctional materials for energy and oncology applications.