Encapsulation of Pd Nanoparticles in Covalent Triazine Frameworks for Enhanced Photocatalytic CO₂ Conversion

Photoreduction of CO2 into solar fuels is an appealing solution to simultaneously mitigate environmental problems and energy crisis, but photocatalyst activity and product selectivity remain challenging. Herein, ultrafine Pd nanoparticles immobilized in an imine-linked covalent triazine framework (Pd@Imine-CTF) are successfully prepared via a wet-chemistry approach. The resultant Pd@Imine-CTF exhibits a highly porous structure, which exposes more active sites and promotes CO2 adsorption and diffusion for photocatalysis. The ultrasmall Pd nanoparticles are confined and stabilized because of the strong interaction between Pd and pyridinic nitrogen atoms within Imine-CTF, which is beneficial for boosting the charge carrier separation and providing ideal sites for CO2 reduction reactions. Under visible-light irradiation, Pd@Imine-CTF displays excellent photocatalytic performance toward CO2 reduction, yielding CO and CH4 with evolution rates of 85.3 and 21.1 μmol g–1 h–1, respectively, and with a remarkable selectivity of up to 91.8%. This work provides a new protocol for the rational design of CTF-based photocatalyst composites for efficient CO2 conversion

Porphyrin Supramolecular Nanoassembly/C₃N₄ Nanosheet S‑Scheme Heterojunctions for Selective Photocatalytic CO₂ Reduction toward CO

The photocatalytic reduction of CO2 with H2O into valuable chemicals is a sustainable carbon-neutral technology for renewable energy; however, the photocatalytic activity and product selectivity remain challenging. Herein, an S-scheme heterojunction photocatalyst with superior CO2 photoreduction performanceporous C3N4 (CN) nanosheets anchored with zinc(II) tetra(4-cyanophenyl)porphyrin (ZnTP) nanoassemblies (denoted as ZnTP/CN)was designed and prepared via a simple self-assembly process. The constructed ZnTP/CN heterojunction had rich accessible active sites, improved CO2 absorption capacity, and high charge carrier separation efficiency caused by the S-scheme heterojunction. As a result, the obtained ZnTP/CN catalyst exhibited considerable activity for photocatalytic CO2 reduction, yielding CO with a generation rate of 19.4 μmol g–1·h–1 and a high selectivity of 95.8%, which is much higher than that of pristine CN nanosheets (4.53 μmol g–1·h–1, 57.4%). In addition, theoretical calculations and in situ Fourier transform infrared spectra demonstrated that the Zn sites in the porphyrin unit favor CO2 activation and *COOH formation as well as CO desorption, thereby affording a high CO selectivity. This work provides insight into the design and fabrication of efficient S-scheme heterostructure photocatalysts for solar energy storage

Ultrafine Ag Nanoparticles Anchored on Hollow S‑Doped CeO₂ Spheres for Synergistically Enhanced Tetracycline Degradation under Visible Light

Photocatalytic degradation of organic contaminants is thought to be a potential means for resolving the growing challenge of environmental pollution. However, the efficacy is severely constrained by ineffective light harvesting and slow charge separation. Herein, ultrafine Ag nanoparticles immobilized in sulfur-doped hollow CeO2 spheres (denoted Ag/CeO2–xSx) were synthesized through self-assembly and a subsequent heat-treatment strategy. Obtained Ag/CeO2–xSx shows promoted utilization efficiency of light, remarkably improved photogenerated carrier separation efficiency, and enlarged surface area. Coupling the synergetic enhancement of light harvesting and charge separation, optimized Ag/CeO2–xSx exhibits superb photocatalytic tetracycline degradation activity (94.2%, 60 min) under visible light irradiation, and its corresponding rate constant (0.0397 min–1) was nearly 28.4-fold higher than that of commercial CeO2 (0.0014 min–1). This analysis provides a simple method for building high-efficiency photocatalysts for solar light-driven wastewater treatment

Photocatalytic Decarboxylative [3 + 2] and [4 + 2] Annulation of Enynals and γ,σ-Unsaturated <i>N</i>‑(Acyloxy)phthalimides by NaI/PPh₃ Catalysis

A practical and eco-friendly strategy for the radical-mediated decarboxylative [3 + 2] and [4 + 2] annulation of enynals and γ,σ-unsaturated N-(acyloxy)­phthalimides through the photoactivation of an electron donor–acceptor (EDA) complex has been developed. A wide range of primary, secondary, and tertiary alkyl N-hydroxyphthalimide (NHP) esters can be used as suitable substrates for the synthesis of fused ketones without any transition-metal catalysts or oxidants. This protocol features a broad substrate scope, excellent selectivity, and clean reaction conditions

Additional file 1 of Biochemical and molecular characterization of a novel glycerol dehydratase from Klebsiella pneumoniae 2e with high tolerance against crude glycerol impurities

Additional file 1: Table S1. Primers used for PCR in this study

Comparisons of burnout scores by various individual and environmental characteristics.

Comparisons of burnout scores by various individual and environmental characteristics.</p

Bi₂WO₆/C₃N₄ S‑Scheme Heterojunction with a Built-In Electric Field for Photocatalytic CO₂ Reduction

Converting CO2 into renewable fuels by solar energy has been considered an ideal strategy to mitigate the climate crisis and address the fossil fuel depletion problem. However, severe charge carrier recombination and sluggish interfacial reaction dynamics make it a challenge to achieve high conversion efficiency. Herein, a unique 2D/2D step-scheme (S-scheme) photocatalyst of Bi2WO6/C3N4 (BWO/CN) is constructed by a facile electrostatic self-assembly strategy. The ultrathin 2D/2D heterostructure endowed the BWO/CN hybrid with abundant contact interfaces, short charge-transport distance, and relatively more accessible reaction sites. Besides, the differences of work function between CN and BWO induced the formation of a built-in electric field, resulting in much enhanced interfacial charge transfer/separation rates. As a result, the optimized BWO/CN heterojunction exhibits significantly improved photocatalytic performance toward CO2 reduction, which is approximately 2.8-fold higher than that of its CN counterpart. The accelerated S-scheme charge-transfer mechanism is systematically corroborated by X-ray photoelectron spectroscopy, photo-irradiated Kelvin probe force microscopy, and electron spin resonance. This research may provide a facile protocol for the rational design of an S-scheme face-to-face 2D/2D heterojunction for efficient CO2 conversion

Individual characteristics of the study population (N = 623).

Individual characteristics of the study population (N = 623).</p

Stepwise regression analysis of the influencing factors of burnout and its three dimensions (n = 623).

Stepwise regression analysis of the influencing factors of burnout and its three dimensions (n = 623).</p