Challenges of photocatalysis and their coping strategies

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.