Photocatalysis Enhanced by External Fields

Abstract

The efficient conversion of solar energy by means of photocatalysis shows huge potential to relieve the ongoing energy crisis and increasing environmental pollution. However, unsatisfactory conversion efficiency still hinders its practical application. The introduction of external fields can remarkably enhance the photocatalytic performance of semiconductors from the inside out. This review focuses on recent advances in the application of diverse external fields, including microwaves, mechanical stress, temperature gradient, electric field, magnetic field, and coupled fields, to boost photocatalytic reactions, for applications in, for example, contaminant degradation, water splitting, CO2 reduction, and bacterial inactivation. The relevant reinforcement mechanisms of photoabsorption, the transport and separation of photoinduced charges, and adsorption of reagents by the external fields are highlighted. Finally, the challenges and outlook for the development of external‐field‐enhanced photocatalysis are presented.

Reactive Oxygenated Species Generated on Iodide‐Doped BiVO4/BaTiO3 Heterostructures with Ag/Cu Nanoparticles by Coupled Piezophototronic Effect and Plasmonic Excitation

“…This separation can be initiated by several means, including an incomplete compensation of a polarization‐induced depolarization electric field. [ 15b,16 ] Such depolarization fields have been shown to be behave as the driving force for charge separation on the surfaces of piezoelectric semiconductors, [ 17 ] which accumulate charges when being subjected to mechanical strain. On the other hand, with the help of the spontaneous polarization of ferroelectrics to tune the charge separation efficiency of semiconductor photocatalysts, the latter have also been shown to enhance photocatalytic activity, such as the use of TiO 2 /BaTiO 3 core/shell nanowires [ 18 ] and hydrogel‐CuO 2 /BaTiO 3 hybrids [ 19 ] in water splitting.…”

Oxygen Vacant Semiconductor Photocatalysts

“…current situations of energy shortage and ecological damage. [3][4][5][6][7][8][9][10] The above advantages stimulate the exploration and development of high-efficient photocatalyst systems, which is devoted to enhance the photocatalytic performances of catalysts. However, the photocatalytic performance of semiconductors is always restricted by the limited light harvesting ability, rapid recombination of photogenerated electrons and holes and inadequate surface reactive sites, which make them hard to meet the requirements of industrial applications.…”

Insight into the Transition‐Metal Hydroxide Cover Layer for Enhancing Photoelectrochemical Water Oxidation

“…With the increasing demand for clean and sustainable energy, more efforts have been focused on the efficient and low‐cost hydrogen generation [1, 2] . The photoelectrochemical (PEC) cell is regarded as a green and renewable approach for converting solar energy into clean hydrogen energy [3–5] or high value added chemicals [6–10] . However, low PEC efficiency mainly resulted from the high charge recombination and undesirable OER kinetics, [7] still severely hinders its practical applications.…”