Synergistic Redox Reaction for Value-Added Organic Transformation via Dual-Functional Photocatalytic Systems

Abstract

Photocatalytic selective organic transformations provide an efficient synthetic alternative for several industrially relevant chemicals using solar rather than thermal energy. However, in most cases, photocatalytic organic reaction systems involve only reductive or oxidative pathways with the aid of sacrificial reagents as efficient electron acceptors or donors, thus limiting the economic added value. Recently, merging selective organic reductions and oxidations in a dual-functional photocatalytic reaction system has been put forward to tackle this limitation. In this coupled reaction system, both the photogenerated electrons and holes can be simultaneously utilized to generate value-added products, make the overall process more valuable from the economic perspective. In this review, the development of dualfunctional photocatalytic organic synthesis is systemically summarized. Particular emphasis is paid to merging selective organic oxidation and reduction reactions and coupling selective organic transformations with chemical fuel generation (e.g., H2, CO). Also, a personal perspective on future developments in this field is provided. Although still in its infancy, it is expected that this dual-functional technology offers opportunities to develop the next-generation selective organic transformation processes that meet the stringent economic, societal, and ecological expectations.

Metal Halide Perovskite Based Heterojunction Photocatalysts

“…The development of Z-scheme APbX 3 photocatalysts should focus on reactions optimally benefiting from a large driving force. [67] For example, small band gap ABI 3 could be considered for extending the absorption spectrum and optimizing the use of solar light, given that an appropriate stabilization can be found. [35] Additionally, by doping with halides and reducing the halide vacancies, the Fermi level of MHPs in the heterojunction can be finely tuned, so that the junction types will change from a type II to a Z-scheme or vice versa, thus allowing better optimization of heterojunctions for specific reactions with high photocatalytic performance.…”

Photocatalytic Anaerobic Oxidation of Aromatic Alcohols Coupled With H2 Production Over CsPbBr3/GO-Pt Catalysts

“…The selective oxidation of alcohols to carbonyls represents one of the most important reactions in both the fine chemical industry and laboratory research ( Shibuya et al, 2011 ; Yang and Xu, 2013 ; Sharma et al, 2016 ; Xue Yang et al, 2017 ; Liu et al, 2018a ; Huang et al, 2018 ; Li et al, 2020 ; Shang et al, 2021 ); the carbonyl products are widely used intermediates and precursors for the manufacture of perfumes, pharmaceuticals, and dyes ( Liu et al, 2015 ; Agosti et al, 2020 ; Xia et al, 2020 ; Shang et al, 2021 ). Generally, the oxidative dehydrogenation of alcohols is carried out in the presence of chemical oxidants such as iodine, manganese, chromium oxide, or molecular oxygen.…”

“…Generally, the oxidative dehydrogenation of alcohols is carried out in the presence of chemical oxidants such as iodine, manganese, chromium oxide, or molecular oxygen. The utilization of costly and toxic chemical agents not only results in the production of stoichiometric amounts of waste but also often generates overoxidized products ( Mallat and Baiker, 2004 ; Lang et al, 2014 ; Meng et al, 2018a ; Meng et al, 2018b ; Kampouri and Stylianou, 2019 ; Crombie et al, 2021 ; Shang et al, 2021 ). Particularly, the removed protons are consumed by the oxidant in these strategies resulting in the loss of a potentially interesting source of hydrogen gas ( Han et al, 2020 ; Wang et al, 2021 ).…”

Co-electrolysis toward value-added chemicals

“…The optimized NiS/CdS shows high hydrogen evolution and benzaldehyde generation rate as high as 207.8 and 163.8 μmol h −1 , respectively, which are the highest rates for concurrent production of hydrogen and aldehyde ever reported in aqueous solution. Although a few reports have been conducted on photocatalytic parallel chemical precursor conversions [28][29][30][31], more attention should be paid to the development of more cophotocatalysis approaches.…”