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Herein, well‐crystallized ZnTiO3 particles are first prepared by hydrothermal method. A series of S‐scheme heterojunction photocatalysts of ZnTiO3/g‐C3N4 (referred to as ZTO/CN) with different mass ratios are synthesized by successfully doping ZnTiO3 in g‐C3N4 precursors and loading ZnTiO3 onto g‐C3N4 nanosheets by calcination. It is clearly found that the ZnTiO3 particles are successfully loaded on g‐C3N4 nanosheets by the X‐ray diffractometer, energy‐dispersive X‐ray spectra, and high‐resolution transmission electron microscopy images. Moreover, the specific surface area of 3.0% ZTO/CN is higher than that of pure g‐C3N4. Using triethanolamine as the hole sacrificial agent, the highest CO and H2 yields are achieved in the 3.0% ZTO/CN composite catalyst under the xenon lamp irradiation for 1 h. The generation rates of CO and H2 reach 15.19 and 5.77 μmol g−1 h−1, respectively, which are 2.9 and 4.1 times higher than that of pure g‐C3N4. The CO and H2 yields of the ZTO/CN composite catalyst show a trend of increasing and then decreasing with the increasing of ZnTiO3 content, which is due to the fact that excess ZnTiO3 can lead to a reduction of the effective heterojunction interface between ZnTiO3 and g‐C3N4, decreasing the transfer and separation efficiency of photogenerated electrons and holes and thus reducing the photocatalytic activity. [ABSTRACT FROM AUTHOR]

Microwave-assisted catalytic oxidation technology has become an effective technology for rapid removal of organic pollutants in wastewater. In this research, the removal of methyl orange (MO) from aqueous solution by CuFe2O4 loaded on carbon nanotubes (CuFe2O4/CNTs) under microwave irradiation was studied. The effects of different loadings (1:2, 1:4, 1:8) of CuFe2O4 on the dielectric loss, magnetic loss, dielectric loss factor, magnetic loss factor, and reflection loss of composite materials were studied. The results showed that the microwave adsorption performance was improved by loading CuFe2O4 on CNTs. These different composites were further characterized by SEM, FTIR, and XRD techniques. In addition, this article also studied the effects of different microwave irradiation time, pH, and ionic factors on the degradation of MO. In particular, the mechanism of MO degradation by composite materials under different pH conditions was also studied in detail. The results showed that the removal rate reaches 97% with 5 min under the best conditions, and the composite material had good anti-interference performance. This study may provide a new option to degrade organic dye in wastewater treating. [ABSTRACT FROM AUTHOR]

Tetracycline (TCN) is a typical antibiotic with ecological toxicity, which is easy to cause bacterial drug resistance. Single-atom catalysts have a broad application prospect in the remediation of antibiotic polluted water by activated persulfate (PDS), but its catalytic properties are limited because of its high surface energy and easy aggregation. Therefore, in our manuscript, a novel nitrogen doped magnetic graphene oxide confined Fe-Co dual single-atom catalyst (Fe/Co(1:1) (S) -NMGO) was prepared by one-step molten salt assisted high temperature pyrolysis. XPS and AC-HAADF-STEM analysis indicated single-atom Fe and Co existed. Fe and Co atoms were bound to the material mainly through coordination with pyridinic N and pyrrolic N. While single-atom Fe and Co were simultaneously introduced into the modified materials, the removal rate of TCN reached 93.1%, implying the significant synergistic effect of single-atom Fe and Co on TCN removal. Molten salt assisted high-temperature pyrolysis significantly improved the TCN degradation rate. In addition, this research showed that the existence of magnetite nanoparticles was beneficial to improve the separation performance of the single-atom catalysts as well as the catalytic performance. At the same time, the effects of some key parameters (Fe/Co molar ratio, catalyst dosage, PDS dosage, initial pH, coexisting anions and humic acids) on TCN degradation in Fe/Co(1:1) (S) -NMGO/PDS system were also investigated. The catalytic potential in actual water and regeneration performance of the material were also evaluated. The possible activation mechanism and degradation pathway of TCN were proposed. These findings will provide important reference for the future design and application of single-atom-involved catalysts. [Display omitted] • Fe/Co dual single-atom catalyst was prepared by molten salt assisted pyrolysis. • Molten salts could provide a high polarity environment to destroy metal-metal bond. • Single Fe and Co atoms anchored on NMGO are verified by AC-HAADF-STEM. • TCN removal rate in this system could reach 93% at low catalyzer and PDS dosage. • Free radical (SO 4 •− >O 2 •− >HO•) oxidation were the main degradation mechanisms. [ABSTRACT FROM AUTHOR]

The sulfate radical-based advanced oxidation processes (SR-AOPs) are considered to be efficient and environmentally friendly for handling persistent organic pollutants issues. The activation of persulfate (PS) by biochar (BC) materials derived from waste biomass is the current research hotspot in SR-AOPs. Herein, we propose bimetal modified peanut hull-derived biochar (BC-Fe-1-Zn) catalysts to activate PS to degrade tetracycline (TC) with a removal efficiency of 90% in 120 min. The physicochemical properties and reaction mechanisms are well studied through the effective combination of various characterization techniques and experiments. SO 4 •– , •OH and electron transfer are all involved in the degradation of TC and SO 4 •– is the main reactive oxygen species (ROSs). The Fe and Zn oxides and the oxygen-containing functional groups on the catalyst surface are considered as the active sites for the reaction. Moreover, the influences of different factors (such as pH, catalyst dosage, PS dosage and coexisting ions) on the TC remove efficiency are studied. Simultaneously, the TC degradation products and its reasonable degradation paths are analyzed. This work provides new ideas for the rational design of biochar-supported bimetallic catalysts and revealed that using BC-Fe-1-Zn in AOPs technology to environmental remediation is a promising approach. [Display omitted] • Biochar is prepared from peanut hull and applied for activating PDS. • Transition metals Fe and Zn are successfully loaded on biochar to promote electron transfer. • The synthesized catalyst owns large specific surface area, abundant functional groups. • Sulfate radicals and hydroxyl radicals contributed to the degradation of TC. [ABSTRACT FROM AUTHOR]

Recently, persulfate-based advanced oxidation processes (persulfate-AOPs) are booming rapidly due to their promising potential in treating refractory contaminants. As a type of popular two-dimensional material, layered double hydroxides (LDHs) are widely used in energy conversion, medicine, environment remediation and other fields for the advantages of high specific surface area (SSA), good tunability, biocompatibility and facile fabrication. These excellent physicochemical characteristics may enable LDH-based materials to be promising catalysts in persulfate-AOPs. In this work, we make a summary of LDHs and their composites in persulfate-AOPs from different aspects. Firstly, we introduce different structure and important properties of LDH-based materials briefly. Secondly, various LDH-based materials are classified according to the type of foreign materials (metal or carbonaceous materials, mainly). Latterly, we discuss the mechanisms of persulfate activation (including radical pathway and nonradical pathway) by these catalysts in detail, which involve (i) bimetallic synergism for radical generation, (ii) the role of carbonaceous materials in radical generation, (iii) singlet oxygen (1O 2) production and several special nonradical mechanisms. In addition, the catalytic performance of LDH-based catalysts for contaminants are also summarized. Finally, challenges and future prospects of LDH-based composites in environmental remediation are proposed. We expect this review could bring new insights for the development of LDH-based catalyst and exploration of reaction mechanism. [Display omitted] • Systematic introduction of different persulfate activation mechanisms by LDH-based catalysts. • Unique "intercalation effect" of LDH-based catalysts have been discussed. • Discussion on the effect of tailoring the morphology of LDHs for improving catalytic performance. [ABSTRACT FROM AUTHOR]

[Display omitted] Sulfate radical-based advanced oxidation processes (SR-AOPs) have received intensively attention due to the ability and adaptability. Biochar-based catalysts have been regarded as the effective catalysts for activating peroxymonosulfate (PMS) to generate sulfate radicals (SO 4 •-). This article discussed the advance of the PMS activation by biochar-based catalysts. Firstly, the sources and synthesis methods of biochar-based catalysts have been discussed. Secondly, the different activation mechanisms (including radical pathways and non-radical pathways) of pristine biochar, heteroatom doping biochar and biochar composites catalysts for PMS activation are reviewed, respectively, which includes (i) the significant role of persistent radical (PFRs) and the special structures (defects and graphitization) of pristine biochar, (ii) the effects of element doping (especially N atom) and metal species on the biochar catalysts, (iii) the production mechanisms of reactive oxygen species (ROS) and special non-radical mechanism. Thirdly, the influences of PMS and catalysts concentration, temperature, pH, anions and natural organic matter (NOM) on the contaminants degradation process have been presented. Finally, the conclusion and prospects section discussed the challenges and possible future directions for the degradation of contaminants by biochar/PMS systems. This review is expected to provide new ideas for the application of biochar-based catalysts and broaden the ways for the removal of organic contaminants. [ABSTRACT FROM AUTHOR]