Metal Sulfide Photocatalysis: Visible‐Light‐Induced Organic Transformations

Abstract

metal sulfides belong to an important subgroup of semiconductor photocatalysts that could promote a variety of valuable redox reactions under mild conditions. One notable merit of metal sulfides is their relatively smaller bandgaps than metal oxides, which in turn make sure that many of them can directly utilize visible light. Historically, the deployment of metal sulfides for visible-light-induced organic transformations took place shortly after the genesis of the research field of heterogeneous photocatalysis. In this review, we primarily focus on recent state-of-the-art advancements of metal sulfide photocatalysis aimed at visible-light-induced selective organic transformations. Interests in this specific branch of photocatalysis have been rekindled due to the new methods for materials synthesis; the pursuit of new mechanisms; or the integration of metal sulfides with metal oxides, metal nanoparticles or other emerging materials. Thus we categorize them into four sections according to the different strategies in developing novel or more efficient organic processes. Binary and ternary metal sulfides, usually associated with new materials synthesis and mechanistic insights, can be used directly for visible-lightinduced organic transformations. This is the basis of other further developments and will be introduced firstly. Next, the cooperation between metal sulfides and metal oxides or metal nanoparticles can be conducive to many photocatalytic systems. These developments will be discussed in the next two ensuing sections. Furthermore, the integration of metal sulfides with recent developed emerging materials such as metalorganic frameworks (MOFs), graphene and graphitic carbon nitride (g-C 3 N 4 ) will be discussed in another section to highlight the importance of merging metal sulfides with these materials. We attempt to keep an impartial panorama of these four distinctive sections even though the phases of development are quite different among sections, leaving plenty of room for the future expansion of this burgeoning area.

Unraveling Photoexcited Charge Transfer Pathway and Process of CdS/Graphene Nanoribbon Composites toward Visible‐Light Photocatalytic Hydrogen Evolution

“…The characteristic peaks at 3360, 2965, 1710, 1642, 1560, and 1381 cm −1 for GNRs are assigned to OH stretching vibration, CH 2 stretching vibration, CO stretching vibration, CO stretching vibration, and OH bending vibration, respectively . The bands at 1007, 1095, and 1183 cm −1 are ascribed to the stretching vibration modes of the epoxy group (COC) . Notably, after the solvothermal treatment the peak at 1710 cm −1 in the CdS/GNR2 becomes weak, suggesting that the partial reduction of oxygenated groups occurs in the CdS/GNR2 sample.…”

Hollow Structured Metal Sulfides for Photocatalytic Hydrogen Generation

“…Herein, we provide a brief overview of the photocatalytic properties of single metal sulfide compounds that have shown great potentials as photocatalysts towards photocatalytic water splitting. For a detailed discussion about these materials, including various nanostructures and applications, readers may refer to the previous comprehensive reviews …”

“…The semiconductor heterojunction between metal sulfides and metal oxides has been a popular strategy since metal oxides can induce photocatalytic oxidations, while narrow‐bandgap sulfides could broaden the light absorption range of oxides . For example, TiO 2 , a well‐known photocatalyst, still shows limitations in photocatalysis application because of its too wide bandgap, which does not respond to visible light.…”

Visible-light-driven organic transformations integrated with H2 production on semiconductors

“…Among a wide array of heterogeneous photocatalysts, semiconductors ranging from transition metal oxides and sulphides to metal-free carbon nitrides have emerged as the most representative visible light-active solidstate photocatalysts. [13][14][15] Scheme 1 Schematic representation of the dual function of a semiconductorbased photocatalyst for integrated H 2 evolution and organic transformations.…”