Heterogeneous photocatalysis in environmental remediation

Abstract

Semiconductor-based photocatalytic processes have been studied for nearly 15 years due to their many intriguing advantages in environmental remediation and other areas. In this paper, underlying principles and mechanism of the photocatalytic degradation process were discussed, followed by thermodynamics, kinetics, mass transfer effects were discussed. The kinetics of photocatalytic degradation was analysed with the aim of determining the favourable conditions to obtain high quantum yield. Primary parameters that influence the process such as catalyst loading, dissolved oxygen, pH, temperature, light intensity, crystalline structure, etc. have been discussed in detail. Different types of photocatalytic reactors, process efficiencies and applications in environmental engineering as well as in other areas have also been mentioned. The main barrier to the commercialization of the processes is the low quantum yield. However, it is expected that large-scale applications could be achieved with significant progress by improvement of process performance.