Progress in the Utilization Efficiency Improvement of Hot Carriers in Plasmon-Mediated Heterostructure Photocatalysis

Abstract

The effect of plasmon-induced hot carriers (HCs) enables the possibility of applying semiconductors with wide band gaps to visible light catalysis, which becomes an emerging research field in environmental protections. Continued efforts have been made for an efficient heterostructure photocatalytic process with controllable behaviors of HCs. Recently, it has been discovered that the improvement of the utilization of HCs by band engineering is a promising strategy for an enhanced catalytic process, and relevant works have emerged for such a purpose. In this review, we give an overview of the recent progress relating to optimized methods for designing efficient photocatalysts by considering the intrinsic essence of HCs. First, the basic mechanism of the heterostructure photocatalytic process is discussed, including the formation of the Schokkty barrier and the process of photocatalysis. Then, the latest studies for improving the utilization efficiency of HCs in two aspects, the generation and extraction of HCs, are introduced. Based on this, the applications of such heterostructure photocatalysts, such as water/air treatments and organic transformations, are briefly illustrated. Finally, we conclude by discussing the remaining bottlenecks and future directions in this field.

Silver-Copper Oxide Heteronanostructures for the Plasmonic-Enhanced Photocatalytic Oxidation of N-Hexane in the Visible-NIR Range

“…To justify the full-range response under different LED wavelengths (Figure 3b), a combination of different photo-excitation and charge-transfer mechanisms can be taking place [68,69,81,99,129,130]. The different photocatalytic response observed after comparison between Ag-CuO and CuO irradiated with the 405 nm LED (Figure 3a) clearly demonstrates the positive influence of the silver entangled nanostructures.…”

“…Likewise, electrons in the Ag surface can participate in the formation of reactive superoxide anions or relax via thermal energy dissipation [95,131]. The superoxide anions may subsequently react after their photo-induced dissociation (Figure 4a) and contribute to the oxidation of the n-hexane molecules [5,68,69,76,81,105,130,132].…”

Exploitation of Lignocellulose Fiber-Based Biotemplates to Improve the Performance of an Immobilized TiO2 Photocatalyst

“…Recent works [6][7][8][9] have summarized the most relevant achievements regarding the syntheses of materials with excellent photochemical features, as well as the preparation of photocatalytic membranes. Several authors have focused their efforts on the photoactivity improvement impacting the physical properties of photocatalysts (particle size, crystalline phase, preferred orientation) by controlling the synthesis parameters, by doping the semiconductor with a co-catalyst [10][11][12][13] or even by combining the photocatalyst with other materials [14][15][16]. On the other hand, different ways of manufacturing membranes with a catalyst layer on the surface have also been studied, including techniques such as dipcoating, electrospraying, magnetron sputtering, deposition of gas phase photocatalyst nanoparticles and so on [4,17].…”

Electrospinning Ag-TiO2 Nanorod-Loaded Air Treatment Filters and Their Applications in Air Purification

“…Studies of novel photocatalysts with both improvement of the utilization of optical energy in the visible range and separation of electron-hole pairs are invariably meaningful in the air treatment field. In virtue of the plasmon-induced hot-electron effect [ 15 , 16 , 17 ], breakthroughs in the limits of catalytic ability can be applied to conventional photocatalysts. On the other hand, it has been found that the ability to capture photons in the visible range can be improved based on the surface plasmon resonance effect [ 18 , 19 ].…”