The polystyrene（PS） microspheres were prepared from free radical polymerization of styrene by a sol-gel method combined with centrifugal sedimentation. And the ordered macroporous titania was prepared from Ti（BuO）4 in ethanol solution using the mentioned PS microspheres as a template, which was removed from titania by calcination at 450 ℃. SEM images revealed the PS template has a three-dimentional ordered structure with particle diameter of ca. 450 nm and the macroporous titania thus obtained has a pore size of ca. 300 nm. XRD showed the macroporous titania has anatase structure.
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.
