SnS2 with Flower-like Structure for Efficient CO2 Photoreduction under Visible-Light Irradiation

Enhanced photocatalytic performance of SnS2 under visible light irradiation: strategies and future perspectives

Tin(II) sulfide (SnS2) has emerged as a promising candidate for visible light photocatalytic materials. As a member of the transition metal dichalcogenides (TMDs) family, SnS2 features a band gap of approximately 2.20 eV and a layered structure, rendering it suitable for visible light activation with a high specific surface area. However, the application of SnS2 as a visible light photocatalyst still requires improvement, particularly in addressing the high recombination of electrons and holes, as well as the poor selectivity inherent in its perfect crystal structure. Therefore, ongoing research focuses on strategies to enhance the photocatalytic performance of SnS2. In this comprehensive review, we analyze recent advances and promising strategies for improving the photocatalytic performance of SnS2. Various successful approaches have been reported, including controlling the reactive facets of SnS2, inducing defects in the crystal structure, manipulating morphologies, depositing noble metals, and forming heterostructures. We provide a detailed understanding of these phenomena and the preparation techniques involved, as well as future considerations for exploring new science in SnS2 photocatalysis and optimizing performance.

One-Step Fabricated Sn0 Particle on S-Vacancies SnS2 to Accelerate Photoelectron Transfer for Sterling Photocatalytic CO2 Reduction in Pure Water Vapor Environment

Promoting the proton-coupled electron transfer process in order to solve the sluggish carrier migration dynamics is an efficient way to accelerate the photocatalytic CO2 reduction (PCR) process. Herein, through the reduction of Sn4+ by amino and sulfhydryl groups, Sn0 particles are lodged in S-vacancies SnS2 nanosheets. The high conductance of Sn0 particles expedites the collection and transport of photogenerated electrons, activating the surrounding surface of unsaturated sulfur (Sx 2- ) and thus lowering the energy barrier for generation of *COOH. Meanwhile, S-vacancies boost H2 O adsorption while Sx 2- increases CO2 adsorption, as demonstrated by density functional theory (DFT), obtaining a selectivity of 97.88% CO and yield of 295.06 µmol g-1 h-1 without the addition of co-catalysts and sacrificial agents. This work provides a new approach to building a fast electron transfer interface between metal particles and semiconductors, which works in tandem with S-vacancies and Sx 2- to boost the efficiency of photocatalytic CO2 reduction to CO in pure water vapor environment.

Metallocavitins as Advanced Enzyme Mimics and Promising Chemical Catalysts

The supramolecular approach is becoming increasingly dominant in biomimetics and chemical catalysis due to the expansion of the enzyme active center idea, which now includes binding cavities (hydrophobic pockets), channels and canals for transporting substrates and products. For a long time, the mimetic strategy was mainly focused on the first coordination sphere of the metal ion. Understanding that a highly organized cavity-like enzymatic pocket plays a key role in the sophisticated functionality of enzymes and that the activity and selectivity of natural metalloenzymes are due to the effects of the second coordination sphere, created by the protein framework, opens up new perspectives in biomimetic chemistry and catalysis. There are two main goals of mimicking enzymatic catalysis: (1) scientific curiosity to gain insight into the mysterious nature of enzymes, and (2) practical tasks of mankind: to learn from nature and adopt from its many years of evolutionary experience. Understanding the chemistry within the enzyme nanocavity (confinement effect) requires the use of relatively simple model systems. The performance of the transition metal catalyst increases due to its retention in molecular nanocontainers (cavitins). Given the greater potential of chemical synthesis, it is hoped that these promising bioinspired catalysts will achieve catalytic efficiency and selectivity comparable to and even superior to the creations of nature. Now it is obvious that the cavity structure of molecular nanocontainers and the real possibility of modifying their cavities provide unlimited possibilities for simulating the active centers of metalloenzymes. This review will focus on how chemical reactivity is controlled in a well-defined cavitin nanospace. The author also intends to discuss advanced metal–cavitin catalysts related to the study of the main stages of artificial photosynthesis, including energy transfer and storage, water oxidation and proton reduction, as well as highlight the current challenges of activating small molecules, such as H2O, CO2, N2, O2, H2, and CH4.

Heterogeneous catalysis mediated by light, electricity and enzyme via machine learning: Paradigms, applications and prospects

Energy crisis and environmental pollution have become the bottleneck of human sustainable development. Therefore, there is an urgent need to develop new catalysts for energy production and environmental remediation. Due to the high cost caused by blind screening and limited valuable computing resources, the traditional experimental methods and theoretical calculations are difficult to meet with the requirements. In the past decades, computer science has made great progress, especially in the field of machine learning (ML). As a new research paradigm, ML greatly accelerates the theoretical calculation methods represented by first principal calculation and molecular dynamics, and establish the physical picture of heterogeneous catalytic processes for energy and environment. This review firstly summarized the general research paradigms of ML in the discovery of catalysts. Then, the latest progresses of ML in light-, electricity- and enzyme-mediated heterogeneous catalysis were reviewed from the perspective of catalytic performance, operating conditions and reaction mechanism. The general guidelines of ML for heterogeneous catalysis were proposed. Finally, the existing problems and future development trend of ML in heterogeneous catalysis mediated by light, electricity and enzyme were summarized. We highly expect that this review will facilitate the interaction between ML and heterogeneous catalysis, and illuminate the development prospect of heterogeneous catalysis.

Fiber-like ZnO with highly dispersed Pt nanoparticles for enhanced photocatalytic CO2 reduction

Utilizing solar energy to convert carbon dioxide (CO₂) into chemical fuels could simultaneously mitigate the greenhouse effect and fossil fuel crisis. Herein, a heterogeneous photocatalyst of ZnO nanofiber deposited by Pt nanoparticles was successfully synthesized toward photocatalytic CO₂ reduction via radio-frequency thermal plasma and photo-deposition method. The Pt nanoparticles were introduced on the surface of ZnO nanofibers to broaden the light absorption and utilization, increase the additional reaction active sites and facilitate the separation of photo-generated electron/hole pairs. Combined with the natural advantages of short transfer path of charge carriers and self-support effecting in humid reaction environment for nanofibers, the Pt/ZnO hetero-junction nanocomposites displayed superior photocatalytic activity for CO₂ reduction with respect to bare ZnO nanofibers, affording a CO-production rate as high as 45.76 μmol g^-1 h^-1 under 300 W Xe lamp irradiation within a gas-solid reaction system. Furthermore, in-suit Fourier transform infrared (FTIR) spectra were applied to unveil the details during photocatalytic CO₂ reduction. This work presents a hetero-junction nanocomposite photocatalyst based on eco-friendly semiconductor and metal materials.

Facile Insights into Hydrothermal Synthesis of Ultrathin Bi4NbO8Cl Nanosheets for Efficient CO2 Photoreduction

Developing novel two-dimensional photocatalysis is an excellent strategy for high-efficiency CO₂ photoreduction. Herein, for the first time, we demonstrate a facile hydrothermal synthesis method to construct ultrathin Bi₄NbO₈Cl nanosheets using tartaric acid as a complexing agent, which can restrain the speed of nucleation. The ultrathin Bi₄NbO₈Cl nanosheets exhibit excellent catalytic activity of CO and CH₄ production (10.84 and 4.45 μmol g^-1 h^-1), which are up to 1.9 and 1.4 times higher than those of the bulk Bi₄NbO₈Cl, respectively. Photoelectric experiments and mechanism analysis systematically show that the as-obtained enhanced performance should be attributed to the formation of ultrathin Bi₄NbO₈Cl nanosheets, and charge separation and migration are significantly boosted. Therefore, this ultrathin Bi₄NbO₈Cl structure has provided new insights into the controllable preparation of ultrathin nanosheet photocatalysts to effectively improve the catalytic performance.