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In recent years, ZnIn2S4 (ZIS) has garnered attention as a promising photocatalyst due to its attractive properties. However, its performance is hindered by its restricted range of visible light absorption and the rapid recombination of photoinduced holes and electrons. Single-atom co-catalysts (SACs) can improve photocatalytic activity by providing highly active sites for reactions, enhancing charge separation efficiency, and reducing the recombination rate of photo-generated carriers. In this work, we perform high-throughput density functional theory (DFT) computations to search for SACs in ZIS encompassing 3d, 4d, and 5d transition metals as well as lanthanides, considering both substitutional and interstitial sites. For a total of 172 SACs, defect formation energy (DFE) is computed as a function of chemical potential, charge, and Fermi level (EF), leading to the identification of low energy dopants and their corresponding shallow or deep defect levels. Statistical data analysis shows that DFE is highly correlated with the difference in electron affinity between the host (Zn/In/S) atom and the SAC, followed by the electronegativity and boiling point. Among the 60 lowest energy SACs, Co_In, Yb_i, Tc_Zn, Au_S, La_i, Eu_i, Au_i, Ta_In, Hf_In, Zr_In, and Ni_Zn lead to a lowering of the Gibbs free energy for hydrogen evolution reaction, improving upon previous ZIS results. The computational dataset and insights from this work promise to accelerate the experimental design of novel dopants in ZIS with optimized properties for photocatalysis and environmental remediation. 

Abstract Platinum‐based halide perovskites exhibit promising optoelectronic properties along with merits of low‐temperature processing and stability. Current research on Pt halide perovskites is limited to 0D A₂BX₆structure as the ABX₃3D structure is thermodynamically unstable. Herein, the study reports the stabilization of the ABX₃structure into a 2D layered phase, CsPtI₃(DMSO), that is stable up to 181.5 °C. The 2D phase shows an excitonic peak at the absorption edge of 600 nm, indicating quantum confinement. It also exhibits a large Stokes shift due to intersystem crossing (ISC), with a quenched singlet excitonic fluorescence at 610 nm and strong triplet emission at 852 nm. Pt(II) co‐ordinates with dimethyl sulfoxide (DMSO) via σ‐donation of S lone‐pair electrons and π‐ back donation from Pt to S, stabilizing CsPtI₃(DMSO) layered structure. The strong electronic interaction between DMSO and Pt(II) and orbital mixing lead to spin‐orbit‐coupling, facilitating ISC and singlet‐to‐triplet exciton energy transfer. The interaction of Pt and DMSO is further confirmed by addition of thioacetamide (TAA), a strong S‐donor, which retards the formation of 2D layered structure, and directly results in Cs₂PtI₆and Pt. 

Abstract Visible‐light‐driven C−C bond formation utilizing ketyl radical (C_ketyl) species has attracted increasing attention recently, as it provides a direct route for the synthesis of complex molecules. However, the most‐developed homogeneous photocatalytic systems for the generation and utilization of ketyl radicals usually entail noble metal‐based (e. g., Ru and Ir) photosensitizers, which suffer from not only high cost but also potential degradation and hence pose challenges in product separation and purification. In contrast, readily accessible, inexpensive, and recyclable semiconductors represent a class of attractive and alternative photocatalysts but remain much less explored for photocatalytic ketyl radical initiated C−C bond formation. This work demonstrates that a wide range of industrially important chemicals, including substituted chromanes and tertiary alcohols, can be produced on ZnIn₂S₄under visible light irradiation through intramolecular cyclization (C_ketyl−C_sp2) and intermolecular cross‐coupling (C_ketyl−C_sp3) reactions, respectively, using ketyl radicals. A suite of experimental studies aided by computational investigation were carried out to shed light on the mechanistic insights of these two types of ketyl radical initiated C−C coupling reactions on ZnIn₂S₄.