Open Access
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11 August 2025Noble Metal Sites Modulated Cyano-COF for Boosted Photocatalytic O2 to H2O2 Production
Photocatalytic O2 reduction to hydrogen peroxide (H2O2) is a promising chemical synthesis pathway with green property. However, the development of efficient and stable photocatalysts that enable high selectivity and activity remains an urgent scientific challenge. Herein, cyano-based covalent organic framework (cyano-COF) photocatalysts modulated by noble metal sites (i.e., Pt, Pd, Au, and Ag), denoted as Pt/cyano-COF, Pd/cyano-COF, Au/cyano-COF, and Ag/cyano-COF, are designed and synthesized. The cyano-group (-C≡N), acting as a strong electron acceptor, interacts with the noble metal sites to establish an efficient electron transfer pathway, which facilitates the separation of photogenerated charges, optimizes the reaction pathway, and thus enables boosted generation of H2O2 via the two-step single electron oxygen reduction reaction (O2→·O2−→H2O2). Under visible irradiation, Pt/cyano-COF, Pd/cyano-COF, Au/cyano-COF, and Ag/cyano-COF deliver superior H2O2 production rates of 903 ± 24, 1073 ± 35, 963 ± 9, and 851 ± 56 μmol·g−1·h−1, respectively, much higher than that of pristine cyano-COF (577 ± 69 μmol·h−1·g−1). This study offers profound insights into the mechanism of noble metal sites in the solar-driven selective reduction of O2 to H2O2 synthesis.
Open Access
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28 August 2025Initiation of Surface Processes by Resonance IR Laser Excitation—State and Perspectives
A possibility to initiate surface reactions by resonant IR laser radiation has been studied. Several systems have been tried, including those with linkage isomerism, such as CO bound to cations in zeolites, decomposition of adsorbed unstable molecules like ozone or HN3, reactions of vibrationally excited molecules with coadsorbed species, or the effect of resonance excitation of hydroazide acid HN3 upon its ability to induce the protonation of dimethylpyridine adsorbed on silanol groups of silica. In almost all the experiments, the changes caused by irradiation were weak, and isotopic selectivity was rather poor. The choice of systems and possible ways to improve their characteristics are discussed as well as the perspectives of their usage for isotope separation or other practical tasks.
Open Access
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09 October 2025Preparation of CdS-BaZrO3 Heterojunction for Enhanced Photocatalytic Water-Splitting Hydrogen Production
Photocatalytic water splitting using solar light, a promising technical approach for hydrogen production. However, the slow charge transfer and rapid recombination of photogenerated charge carriers in photocatalysis limit their practical application. To address these issues, in this work, we successfully prepared a novel CdS-BaZrO3 (CdS-BZO3) heterojunction via a simple chemical-bath deposition method. The as-prepared heterojunctions facilitate the separation and transportation of photogenerated charges, while also maintaining the high redox-oxid ation ability of the photocatalysts. As a result, CdS-BZO3 heterojunctions show enhanced photocatalytic water-splitting hydrogen production ability without a co-catalyst. Especially, the optimized CdS-BZO3 sample exhibits high photocatalytic activity with a hydrogen production rate of 44.77 μmol/h, which is 4.4 and 2.9 times higher than that of BZO3 and CdS, respectively. At the same time, the CdS-BZO3 heterojunction exhibits good stability in the photocatalytic hydrogen production cycle test. This work provides a reference for the heterostructure construction of perovskite-based photocatalysts to improve photocatalytic performance.
Open Access
Article
24 October 2025N-TiO2 Photonic and Quantum Photocatalytic Efficiency Determined by Monte Carlo Simulation
Nitrogen-modified titanium dioxide (N-TiO2) is proposed as an alternative to improve solar light absorption in photocatalytic applications. Due to its high chemical stability and low toxicity, various synthesis methods have been developed, yielding materials with different properties. Evaluating its performance compared to other photocatalysts requires calculating the quantum efficiency, which involves appropriate mathematical models to interpret experimental data. This study used a Monte Carlo approach to determine the local volumetric rate of photon absorption (LVRPA). TiO2 and N-TiO2 were synthesized via the sol-gel method using urea as the nitrogen source, and commercial TiO2 P-25 was used as a reference. Formic acid and salicylic acid were chosen as model pollutants due to their differing adsorption behavior on TiO2. Three light sources were used: UVA, white, and blue light. Nitrogen doping increased quantum efficiency for formic acid degradation under UVA from 2.4 to 3.5 (46% increase) and salicylic acid from 1.0 to 2.1 (110% increase). P-25 showed the highest efficiencies under UVA, with 6.2 for formic acid and 5.2 for salicylic acid. Under white light, salicylic acid degradation efficiency doubled from 0.4 to 0.8 after nitrogen doping. No activity was observed for formic acid with undoped TiO2 under white light, but N-TiO2 achieved 1.1. Under blue light, no activity was detected for formic acid, while salicylic acid degradation showed efficiencies of 0.3 (N-TiO2) and 0.2 (P-25). Quantum efficiency was highest under UVA, indicating that nitrogen doping improves visible light response but does not surpass UVA performance.
