Hot‐Electron‐Mediated Photochemical Reactions: Principles, Recent Advances, and Challenges

Abstract

Hot electron chemistry has drawn tremendous attention from applications related to materials, energy, sensing, and catalysis. The plasmon‐induced generation of hot electrons and their transfer behavior are very important for understanding plasmonic‐enhanced applications and for achieving practically useful efficiency. From a plasmonic perspective, well‐designed plasmonic structures that can manipulate surface plasmons are able to enhance the efficiencies of hot electron‐based processes. This progress report summarizes the recent experimental and theoretical advances on the hot electron effect, emphasizing the crucial role of surface plasmons that are highly designable by using metal nanostructures. In particular, recent breakthroughs in the emerging fields of heterogeneous catalysis based on the hot electron effect are highlighted. Important design principles, mechanisms, and concepts, as well as challenges and perspectives, are illustrated and discussed.

Reaction Pathway Dependence in Plasmonic Catalysis: Hydrogenation as a Model Molecular Transformation

“…It has been established that the localized surface plasmon resonance excitation can contribute to the enhancement in the rate of molecular transformations by a variety of mechanisms. These include local heating by plasmon decay and charge‐transfer processes (through direct and indirect mechanisms) that occur as a result of the generation of localized surface plasmon resonance‐excited hot electrons and holes …”

“…[11][12][13][14] Plasmonic nanocatalysis has become attractive towards the development of more environmentally friendly processes because it enables the utilization of visible/solar light as ag reen energy input to drivea nd control av ariety of transformations. [3,[15][16][17][18][19] In fact, silver and gold nanoparticles as well as their hybridsw ith metal-oxides and graphene-based materials have been investigated as plasmonic catalysts, in whichs ignificant enhancements have been reported under localized surfacep lasmon resonance excitation. [20][21][22][23][24][25][26][27][28][29] It has been established that the localizeds urfacep lasmon resonancee xcitation can contributet ot he enhancement in the rate of molecular transformations by av arietyo fm echanisms.…”

Photothermally Enhanced Plasmon‐Driven Catalysis on Fe5C2@Au Core–Shell Nanostructures

“…Later, 4‐nitrothiophenol (4‐NTP) has also been observed to be dimerized into DMAB through a plasmon‐induced route . Recent studies have shown that the plasmon‐induced reactions can be mainly promoted by the hot electrons generated through surface plasmon decay or a local thermal effect on metal surface upon laser excitation, while the reaction atmosphere as well as the SERS substrate can also greatly affect the reaction process . More recently, it has been demonstrated that a plasmon‐exciton co‐driven pathway can effectively tune such coupling reactions .…”

Plasmonic and Photonic Effects on Hydrogen Evolution over Chemically Modified Titania Inverse Opals

“…Plasmon enhanced photocatalysis is one of the hot topics of research in the current decade ,. Photonic crytstals with plasmonic functionality offers promising route to enhance solar‐to‐chemical energy conversion by overcoming the constraints of conventional solar‐light driven photocatalysis . The fabrication of inverse opals made of semiconductor materials such as TiO 2 offers the utilization of photonic as well as structural properties of the inverse opal structures in photocatalytic processes.…”