Challenges of photocatalysis and their coping strategies

Abstract

The photocatalysis process comprises both the catalytic steps, such as diffusion, adsorption, surface reaction, and desorption, and the photoelectric conversion steps, including light harvesting, semiconductor excitation, photo-charge migration, and photoelectron-hole separation. The strategic development of efficient photocatalysts and photocatalytic reaction technologies is crucial for coping with the challenges of photocatalysis in practical applications. First, photocatalytic performance greatly depends on the physical and chemical properties of the photocatalyst, such as light absorbance, excitation, photocarrier recombination, instinct activity, molecule adsorption, and activation. Meanwhile, optimizing the photocatalytic reaction process can also improve the photocatalytic efficiency by inhibiting photoelectron-hole recombination, diminishing the secondary pollution from by-products, and avoiding poisoning deactivation. Herein, we outline the recent achievements in photocatalysis development and application. Photocatalysis has received increasing attention owing to its potential application in the fields of environment, energy, photosynthesis, medicine, and health. The practical application of photocatalysis is still limited by the low photocatalytic efficiency and poor stability. By means of the comprehensive study of the fundamentals of photocatalysis, this review summarizes recent developments in improving photocatalytic efficiency by designing new photocatalysts and optimizing reaction processes to promote light absorption and utilization, inhibit photoelectron-hole recombination, enhance instinct activity, and diminish poisoning deactivation. Some representative powerful photocatalysts have been designed by composition adjusting, morphology and structure tailoring, pore-channel engineering, surface chemistry modifying, etc. Meanwhile, the reaction process can also be optimized by coupling photocatalysis with other advanced oxidation technology. The strategic development of efficient photocatalysts and photocatalytic reaction technologies is crucial for coping with the challenges of photocatalysis in practical applications. Optimizing the photocatalytic reaction process can also improve the photocatalytic efficiency by inhibiting photoelectron-hole recombination, diminishing secondary pollution from by-products, and avoiding poisoning deactivation. Herein, we outline the recent achievements in photocatalysis development and application.