Search

In this study, we introduce a highly effective non-metallic iodine single-atom catalyst (SAC), referred to as I-NC, which is strategically confined within a nitrogen-doped carbon (NC) scaffold. This configuration features a distinctive C-I coordination that optimizes the electronic structure of the nitrogen-adjacent carbon sites. As a result, this arrangement enhances electron transfer from peroxymonosulfate (PMS) to the active sites, particularly the electron-deficient carbon. This electron transfer is followed by a deprotonation process that generates the peroxymonosulfate radical (SO5•−). Subsequently, the SO5•− radical undergoes a disproportionation reaction, leading to the production of singlet oxygen (1O2). Furthermore, the energy barrier for the rate-limiting step of SO5•− generation in I-NC is significantly lower at 1.45 eV, compared to 1.65 eV in the NC scaffold. This reduction in energy barrier effectively overcomes kinetic obstacles, thereby facilitating an enhanced generation of 1O2. Consequently, the I-NC catalyst exhibits remarkable catalytic efficiency and unmatched reactivity for PMS activation. This leads to a significantly accelerated degradation of pollutants, evidenced by a relatively high observed kinetic rate constant (kobs ~ 0.436 min−1) compared to other metallic SACs. This study offers valuable insights into the rational design of effective non-metallic SACs, showcasing their promising potential for Fenton-like reactions in water treatment applications. Electronic structure modulation of active sites is important for Fenton-like catalysis. A non-metallic iodine single-atom catalyst with C-I coordination is reported here, which can effectively activate peroxymonosulfate into 1O2 for water treatment. [ABSTRACT FROM AUTHOR] more...

Comprehensive Summary: The saline and buffered environment in actual wastewater imposes higher demands on Fenton and Fenton‐like catalytic systems. This study developed a MoS2 co‐catalytic Fe2O3 Fenton‐like system with controllable Lewis acid‐base sites, achieving efficient treatment of various model pollutants and actual industrial wastewater under neutral buffered environment. The acidic microenvironment structured by the edge S sites (Lewis basic sites) in the MoS2/Fe2O3 catalyst is susceptible to the influence of Lewis acidic sites constructed by Mo and Fe element, affecting catalytic performance. Optimizing the ratio of precursor amounts ensures the stable presence of the acidic microenvironment on the surface of catalyst, enabling the beneficial co‐catalytic effect of Mo sites to be realized. Furthermore, it transcends the rigid constraints imposed by the Fenton reaction on reaction environments, thereby expanding the applicability of commonplace oxides such as Fe2O3 in actual industrial water remediation. [ABSTRACT FROM AUTHOR] more...

Singlet oxygen (1O2) is an essential reactive species responsible for selective oxidation of organic matter, especially in Fenton‐like processes. However, due to the great limitations in synthesizing catalysts with well‐defined active sites, the controllable production and practical application of 1O2 remain challenging. Herein, guided by theoretical simulations, a series of boron nitride‐based single‐atom catalysts (BvBN/M, M=Co, Fe, Cu, Ni and Mn) were synthesized to regulate 1O2 generation by activating peroxymonosulfate (PMS). All the fabricated BvBN/M catalysts with explicit M−N3 sites promoted the self‐decomposition of the two PMS molecules to generate 1O2 with high selectivity, where BvBN/Co possessed moderate adsorption energy and d‐band center exhibited superior catalytic activity. As an outcome, the BvBN/Co‐PMS system coupled with membrane filtration technology could continuously transform aromatic alcohols to aldehydes with nearly 100 % selectivity and conversion rate under mild conditions, suggesting the potential of this novel catalytic system for green organic synthesis. [ABSTRACT FROM AUTHOR] more...

Copper (Cu) is evidenced to be effective for constructing advanced catalysts. In particular, Cu2O is identified to be active for general catalytic reactions. However, conflicting results regarding the true structure‐activity correlations between Cu2O‐based active sites and efficiencies are usually reported. The structure of Cu2O undergoes dynamic evolution rather than remaining stable under working conditions, in which the actual reaction cannot proceed over the prefabricated Cu2O sites. Therefore, the dynamic construction of Cu2O active sites can be developed to promote catalytic efficiency and reveal the true structure‐activity correlations. Herein, by introducing the redox pairs of Cu2+ and reducing sugar into a photocatalysis system, it is clarified that the Cu2O sub‐nanoclusters (NCs), working as novel active sites, are on‐site constructed on the substrate via a photoinduced pseudo‐Fehling's route. The realistic interfacial charge separation and transformation capacities are remarkably promoted by the dynamic Cu2O NCs under the actual catalysis condition, which achieves a milestone efficiency for nitrate‐to‐ammonia photosynthesis, including the targets of production rate (1.98±0.04 mol gCu−1 h−1), conversion ratio (94.2±0.91 %), and selectivity (98.6 %±0.55 %). The current work develops an effective strategy for integrating the active site construction into realistic reactions, providing new opportunities for Cu‐based chemistry and catalysis sciences research. [ABSTRACT FROM AUTHOR] more...

To date, the chemical conversion of organic pollutants into value‐added chemical feedstocks rather than CO2 remains a major challenge. Herein, we successfully developed a coupled piezocatalytic and advanced oxidation processes (AOPs) system for achieving the conversion of various organic pollutants to CO. The CO product stems from the specific process in which organics are first oxidized to carbonate through peroxymonosulfate (PMS)‐based AOPs, and then the as‐obtained carbonate is converted into CO by piezoelectric reduction under ultrasonic (US) vibration by using a Co3S4/MoS2 catalyst. Experiments and DFT calculations show that the introduction of Co3S4 not only effectively promotes the transfer and utilization of piezoelectric electrons but also realizes highly selective conversion from carbonate to CO. The Co3S4/MoS2/PMS system has achieved selective generation of CO in actual complex wastewater treatment for the first time, indicating its potential practical applicability. [ABSTRACT FROM AUTHOR] more...

Metal–organic frameworks (MOFs) are potential photocatalytic materials for CO2 reduction, however, still limited by their low efficiency. In this work, cobalt decorated UiO-66-NH2 (xCoNU, x presents the mass friction of cobalt) were successfully synthesized through an economic NaBH4 treating method and applied for CO2 photocatalytic reduction. It was confirmed that cobalt worked as the active site in the system, and an optimized CO yielding rate of 1.93 mmol g−1 h−1 in 3 h was achieved on 5CoNU, which is 10.2 times higher than that of UiO-66-NH2. Characterization results revealed that the highly dispersed cobalt in xCoNU accelerates the charge separation and electron transport in the photocatalytic system, improving the photocatalytic CO2 reduction performance. This work provides a simple and convenient method to modify MOFs with metal cocatalyst, and is expected to advance the development of efficient CO2 photoreduction catalysts. [ABSTRACT FROM AUTHOR] more...

Catalytic hydrogen peroxide (H2O2) generation from oxygen and water enables a sustainable environment to operate in an effective and green energy‐to‐chemical conversion way, which has attracted increasing interest in the fields of energy production and environment treatment. In light of this, tremendous progresses and developments have been made during the past decades in catalytic H2O2 production for pollutant removal from three perspectives including photocatalysis, electrocatalysis or chemical activation. Herein, we critically review the state‐of‐the‐art developments over various procedures of H2O2 generation and its further application, with the existence of photocatalysts, electrocatalysts, and catalysts, respectively. Benefiting from extensively experimental and theoretical investigations, the performance and stability of H2O2 generation and its utilization can be maneuvered by devising catalytic platform based on numerous catalysts with predominant electronic, chemical and physical properties, which endow the catalysts with efficient electrons transportation, abundant active sites, and sufficient oxygen adsorption for H2O2 generation. Furthermore, this review also discusses the formation mechanism of H2O2 by 2e‐ORR and 2e‐WOR, as well as its functional process of activating and removing pollutants, and summarizes the design principles of various catalysts by focusing on the formation of H2O2. We finally highlight the specific challenges and prospects related to the utilization of catalysts and envision the possible future development trends in the fields of pollutant removal. [ABSTRACT FROM AUTHOR] more...

The universal limit on the pH conditions is disturbing peroxymonosulfate (PMS)‐triggered high‐valent iron‐oxo systems in environmental applications. Here, we propose for the first time the construction of a neutral microenvironment on the surface of Zn−Fe layered double hydroxide (ZnFe‐LDH) by using the amphoteric properties of zinc hydroxide, which continuously generates ≡FeIV=O over a wide pH range of 3.0–11.0 in activating PMS. The ≡Zn(OH)2 moiety offers a neutral microenvironment at the phase interface, which mitigates the self‐decomposition of ≡FeIV=O by protons and the hydrolysis reaction of iron by hydroxyl groups, which is supported by the Mossbauer spectra, density functional theory calculations and designed experiments. Consequently, ZnFe‐LDH/PMS can satisfy the stability in long‐term experiments, selectivity under conditions with high salinity or natural organic matter and efficient treatment of actual wastewater. [ABSTRACT FROM AUTHOR] more...

Construction of efficient photocatalysts without noble metals for selective photoreduction of CO2 to CH4 remains a challenge. Herein, Cu cocatalyst modified TiO2 photocatalysts were successfully prepared by a convenient solvothermal method. The selectivity of photocatalytic CO2 reduction can be well regulated through valence state and loading amount of Cu. Cu (0) is beneficial to H2 evolution, while high valence Cu contributes to higher CH4 selectivity. The loaded Cu cocatalyst promoted the separation of photogenerated electron-hole and served as the active site for CO2 photoreduction, significantly improving the photocatalytic activity of TiO2. The highest CH4 generation rate of 12.52 μmol g−1 h−1 was achieved on 0.1CT with high CH4 selectivity of 96.9% toward carbon products, which is 397 times higher than pure TiO2 in terms of electrons involved in the reaction. The current work provides significant guidance for the construction of efficient photocatalysts for regulating product selectivity toward CO2 photoreduction. [ABSTRACT FROM AUTHOR] more...

The low utilization of visible light and quick recombination of photo-generated electron–hole pairs of g-C3N4 hinder the enhancement of its photocatalytic performance. Modification of g-C3N4 with dual cocatalysts can promote the spatial separation of carriers, thus showing good redox ability. Here, the efficient photocatalyst g-C3N4/MnO2/Pt with dual cocatalysts is prepared in two steps including calcination- and photo-deposition process. Pt and MnO2 nanoparticles are used as electron and hole collectors, respectively. The g-C3N4/MnO2/Pt composite is characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS). Compared with pure g-C3N4, the photocatalytic hydrogen (H2) evolution performance of g-C3N4/MnO2/Pt is significantly enhanced. And the H2 production yield of g-C3N4/MnO2/Pt is more than 8 times as high as that of g-C3N4/Pt. Meanwhile, the prepared photocatalyst can help promoting peroxymonosulfate activation to degrade organic pollutants. Its degradation performances for phenol, sulfadiazine, bisphenol A, Rhodamine B, and methyl orange are significantly improved, owing to the generation of reactive oxygen species. This work provides a new strategy for the application of photo-generated electrons of g-C3N4 with dual cocatalyst in H2 evolution and environmental remediation. [ABSTRACT FROM AUTHOR] more...