Photocatalysis fundamentals and surface modification of TiO2 nanomaterials

As a green and sustainable technology, heterogeneous photocatalysis using semiconductors has received much attention during the past decades because of its potential to address energy and environmental problems. Among various semiconductors, TiO2 has been regarded as the best and most widely investigated photocatalyst in the past 10 years. Based on the fundamentals of photocatalysis and surface chemistry of TiO2 nanomaterials, we herein summarize and discuss the achievements in the different surface modification strategies employed to date such as surface doping and sensitization, construction of surface heterojunctions, loading of nano-sized co-catalysts, increase in the accessible surface areas, and usage of surface F effects and exposure of highly reactive facets. Especially, the interesting synergistic effects of these different surface modification strategies deserve more attention in the near future. Studying these important advances in photocatalysis fundamentals, and surface chemistry and modification may offer new opportunities for designing highly efficient TiO2-based and non-TiO2-based photocatalysts for solar fuel production, environmental remediation, organic photosynthesis, and other related fields such as solar cell device fabrication, thermal catalysis, and separation and purification.