Author
Gaoling Wei
Bio: Gaoling Wei is an academic researcher. The author has contributed to research in topics: Catalysis & Magnetite. The author has an hindex of 15, co-authored 32 publications receiving 1261 citations.
Topics: Catalysis, Magnetite, Catalytic oxidation, Adsorption, Chemistry
Papers
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TL;DR: The present study shows that the release of OPs from a wide variety of commercial products and wastewater discharge might be considered as primary emission sources and that high potential of long-range atmospheric transport and persistence of OP would be responsible for their presence in various matrices on a global scale.
822 citations
TL;DR: In this article, the synthesis and characterization of manganese substituted spinel ferrites, and their application as catalysts for formaldehyde oxidation were investigated by XRD, Raman, XPS spectroscopy and TG-DSC analysis.
Abstract: The work reports the synthesis and characterization of manganese substituted spinel ferrites, and their application as catalysts for formaldehyde oxidation. Structure and cationic coordination environment of the prepared catalysts were investigated by XRD, Raman, XPS spectroscopy and TG-DSC analysis. Temperature-programmed reduction (TPR) was used to measure the reducibility of catalysts. The characterization results reveal the formation of spinel structure in all the synthetic catalysts. The Mn cations enrich on the surface in the valence of +3 and +4. Mn substitution obviously increases the lattice oxygen content, facilitates the reduction of ferrite, and enhances the oxidative ability of Fe 3+ and Mn cations on the catalyst surface. The presence of Mn cations in spinel ferrite greatly improves its catalytic activity in formaldehyde oxidation, evidenced by the obvious decrease of 90% formaldehyde conversion temperature. The studied catalyst also displays high stability and superior activity in the presence of water vapor, which presents an applied interest. The remarkable effect of Mn substitution on the promoted formaldehyde oxidation over spinel ferrite catalysts was discussed in view of reaction mechanism and variations in microstructural environment and physicochemical properties of spinel ferrite.
137 citations
TL;DR: The present study comprehensively reviewed the occurrence, fate and ecological risk of CPs in various environmental matrices in Asia and suggested inhalation, dust ingestion and dietary intake are strongly suggested as the major routes of human exposure.
116 citations
TL;DR: In this article, the effect of incorporation of transition metals (i.e., Co, Mn, Cr, and Ni) into the magnetite on the reactivity towards Oxone activation was investigated at neutral pH.
Abstract: In this study, the effect of incorporation of transition metals (i.e., Co, Mn, Cr, and Ni) into the magnetite on the reactivity towards Oxone activation was investigated at neutral pH. The magnetite samples were characterized by XRD and EXAFS. Co, Cr, and Ni were in the valences of +2, +3, and +2, respectively, while Mn was in the valences of +2 and +3. These cations occupied the octahedral sites of magnetite, but the distribution of Mn and Ni on the octahedral sites of magnetite surface increased with an increase of substitution extent. The activity of magnetites in Oxone activation was investigated through Acid Orange II (AOII) degradation at an initial pH of 7.0 with or without phosphate-buffered solution. In neutral medium, the AOII degradation by Mn, Cr, and Ni substituting magnetites followed pseudo-first-order kinetics. The incorporation of Co, Mn, and Ni improved the catalytic activity of magnetite in the order Mn tert -butyl alcohols. The different effects of studied substitutions on the reactivity of magnetite were discussed in views of reactive radical species and microstructural environment.
113 citations
TL;DR: In this paper, nonlinear least squares fitting (NLLSF) was used to calculate the relative Co and Fe contents of a series of synthesized Co-substituted magnetite samples with different Co doping levels.
91 citations
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TL;DR: In this paper, the authors provide a state-of-the-art review on the development in heterogeneous catalysts including single metal, mixed metal, and nonmetal carbon catalysts for organic contaminants removal, with particular focus on peroxymonosulfate (PMS) activation.
Abstract: Sulfate radical-based advanced oxidation processes (SR-AOPs) employing heterogeneous catalysts to generate sulfate radical (SO4 −) from peroxymonosulfate (PMS) and persulfate (PS) have been extensively employed for organic contaminant removal in water. This article aims to provide a state–of–the–art review on the recent development in heterogeneous catalysts including single metal, mixed metal, and nonmetal carbon catalysts for organic contaminants removal, with particular focus on PMS activation. The hybrid heterogeneous catalyst/PMS systems integrated with other advanced oxidation technologies is also discussed. Several strategies for the identification of principal reactive radicals in SO4 −–oxidation systems are evaluated, namely (i) use of chemical probe or spin trapping agent coupled with analytical tools, and (ii) competitive kinetic approach using selective radical scavengers. The main challenges and mitigation strategies pertinent to the SR-AOPs are identified, which include (i) possible formation of oxyanions and disinfection byproducts, and (ii) dealing with sulfate produced and residual PMS. Potential future applications and research direction of SR-AOPs are proposed. These include (i) novel reactor design for heterogeneous catalytic system based on batch or continuous flow (e.g. completely mixed or plug flow) reactor configuration with catalyst recovery, and (ii) catalytic ceramic membrane incorporating SR-AOPs.
1,802 citations
TL;DR: A literature review on environmental application of peroxymonosulfate (PMS) in degradation of contaminants to clarify the performance of PMS is carried out in this paper, which describes the PMS usage in remediation of environmental pollutants with focus on the different methods of activation and the effect of main operational parameters on PMS-based processes.
1,650 citations
TL;DR: This Review systematically documents the progresses and developments made in the understanding and design of heterogeneous catalysts for VOC oxidation over the past two decades and addresses in detail how catalytic performance is often drastically affected by the pollutant sources and reaction conditions.
Abstract: It is well known that urbanization and industrialization have resulted in the rapidly increasing emissions of volatile organic compounds (VOCs), which are a major contributor to the formation of secondary pollutants (e.g., tropospheric ozone, PAN (peroxyacetyl nitrate), and secondary organic aerosols) and photochemical smog. The emission of these pollutants has led to a large decline in air quality in numerous regions around the world, which has ultimately led to concerns regarding their impact on human health and general well-being. Catalytic oxidation is regarded as one of the most promising strategies for VOC removal from industrial waste streams. This Review systematically documents the progresses and developments made in the understanding and design of heterogeneous catalysts for VOC oxidation over the past two decades. It addresses in detail how catalytic performance is often drastically affected by the pollutant sources and reaction conditions. It also highlights the primary routes for catalyst deactivation and discusses protocols for their subsequent reactivation. Kinetic models and proposed oxidation mechanisms for representative VOCs are also provided. Typical catalytic reactors and oxidizers for industrial VOC destruction are further discussed. We believe that this Review will provide a great foundation and reference point for future design and development in this field.
1,074 citations
TL;DR: The physicochemical characteristics of spinels such as their compositions, structures, morphologies, defects, and substrates have been rationally regulated through various approaches and can yield spinels with improved ORR/OER catalytic activities, which can further accelerate the speed, prolong the life, and narrow the polarization of fuel cells, metal-air batteries, and water splitting devices.
Abstract: Spinels with the formula of AB2O4 (where A and B are metal ions) and the properties of magnetism, optics, electricity, and catalysis have taken significant roles in applications of data storage, biotechnology, electronics, laser, sensor, conversion reaction, and energy storage/conversion, which largely depend on their precise structures and compositions. In this review, various spinels with controlled preparations and their applications in oxygen reduction/evolution reaction (ORR/OER) and beyond are summarized. First, the composition and structure of spinels are introduced. Then, recent advances in the preparation of spinels with solid-, solution-, and vapor-phase methods are summarized, and new methods are particularly highlighted. The physicochemical characteristics of spinels such as their compositions, structures, morphologies, defects, and substrates have been rationally regulated through various approaches. This regulation can yield spinels with improved ORR/OER catalytic activities, which can furth...
1,036 citations
TL;DR: Novel Mn1.8Fe1.2O4 nanospheres were synthesized and used to activate PMS for the degradation of bisphenol A (BPA), a typical refractory pollutant, and a synergistic effect between solid-state Mn and Fe was identified in control experiments.
Abstract: A high-efficient, low-cost, and eco-friendly catalyst is highly desired to activate peroxides for environmental remediation. Due to the potential synergistic effect between bimetallic oxides’ two different metal cations, these oxides exhibit superior performance in the catalytic activation of peroxymonosulfate (PMS). In this work, novel Mn1.8Fe1.2O4 nanospheres were synthesized and used to activate PMS for the degradation of bisphenol A (BPA), a typical refractory pollutant. The catalytic performance of the Mn1.8Fe1.2O4 nanospheres was substantially greater than that of the Mn/Fe monometallic oxides and remained efficient in a wide pH range from 4 to 10. More importantly, a synergistic effect between solid-state Mn and Fe was identified in control experiments with Mn3O4 and Fe3O4. Mn was inferred to be the primary active site in the surface of the Mn1.8Fe1.2O4 nanospheres, while Fe(III) was found to play a key role in the synergism with Mn by acting as the main adsorption site for the reaction substrates....
596 citations