CHEMOSPHERE
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2021
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IF 7.086
Guo-Qiang Li,Zheng-Yang Huo,Qian-Yuan Wu,Zhuo Chen,Yin-Hu Wu,Yun Lu,Hong-Ying Hu
Recently, ultraviolet light-emitting diodes (UV-LEDs) and chlorine combined system has been employed as an emerging advanced oxidation process . However, UV-LEDs were commonly considered as monochromatic UV sources. In this study, the obvious quantum yields of chlorine photolysis under 265 nm and 280 nm LEDs irradiations were investigated with treating LEDs as polychromatic UV sources. Particularly, Φ obs-poly of HOCl and OCl⁻ for 265 nm LED were found to be 1.50 and 0.70 mol E −1 , respectively, whereas Φ obs-poly of HOCl and OCl⁻ for 280 nm LED were 1.28 and 0.64 mol E −1 , respectively. It was identified that Φ obs-poly were 5.66–14.63 % lower than Φ obs-mono . This suggests that obvious quantum yield using peak emission wavelength would overestimate the true quantum yield. The production of radical species in LED UV/chlorine systems were determined by the degradation of BA , and illustrated by a mathematical model. Different trends were observed for 265 nm and 280 nm LED UV/chlorine systems as pH increased from 5.0 to 10.0. As pH increased, the formation of OH continuously decreased in both 265 nm and 280 nm LED systems. The formation of Cl increased at neutral pH and more Cl and OH were formed due to the higher molar absorbance coefficient at 280 nm. The chlorine dose-dependent effects on radical productions at pH of 5.0, 7.5 and 10.0 were also assessed. At pH of 5.0, OH was the main radical product and had linear correlation with chlorine dose. At pH of 7.5, the productions of OH and Cl showed similar profiles that increased rapidly at low chlorine dosage and then slowed down.
研究领域:
环境科学
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化学工程
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DOI
PubMed
高影响因子
Sustainable Energy & Fuels
·
2024
·Vol. 8
·期 19
·4496-4506
·
IF 5
Jifang Zhang,Jinde Sun,Chengcheng Suo,Wei Li,Sha Luo,Bing Tian,Chunhui Ma,Shouxin Liu
The low efficiency of photogenerated charge transfer to generate reactive oxygen species is the main factor that limits the photocatalytic activity of ZnIn2S4 (ZIS)-based materials in lignin depolymerization. In this work, we prepared an efficient ZIS catalyst with a hexagonal crystal structure and three-dimensional flower-like micromorphology by a solvothermal method. The ZIS catalyst possessed abundant active sites and efficient light-harvesting ability. Sulfur vacancies (Sv) were introduced into the ZIS photocatalyst (ZIS-Sv) to enhance its electron-withdrawing ability and promote the separation and transfer of photogenerated charges. Using the ZIS-Sv photocatalyst, the conversion rate of Cα–Cβ bonds in the β-O-4 dimer reached 96.31% and the molar yields (selectivity) of phenol and acetophenone were 695.17 μmol g−1 h−1 (85.14%) and 610.66 μmol g−1 h−1 (74.73%), respectively (with a ZIS-Sv0.6 concentration of 1 mg ml−1, irradiation time of 6 h, ethanol content of 90%, pH of 5, and 2-phenoxyacetophenone concentration of 1 mg ml−1). The photocatalytic depolymerization of dioxane lignin by the ZIS-Sv photocatalyst reached an efficiency of 80.42%. Catalyst characterization results and mechanism studies indicated that Sv promoted effective electron adsorption to generate oxygen radicals ˙OH and ˙O2− through O2 single-electron reduction and H2O decomposition, respectively. Then, the oxygen radicals combined with C-centered radicals to form unstable intermediates, further breaking lignin linkages, which finally formed an efficient indirect oxidation process. It is expected that introducing Sv into ZIS materials is a useful strategy to obtain photocatalysts for Cα–Cβ cleavage to realize efficient photocatalytic lignin depolymerization.
研究领域:
化学工程
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环境科学
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DOI
高影响因子
Reaction Chemistry & Engineering
·
2022
·Vol. 7
·期 7
·1660-1670
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IF 5.2
Yanzhe Yu,Yonggen Lu,Xisong Cheng,Lei Han,Changling Yang
Mesophase pitch is made via thermal polymerization from raw pitch with smaller molecular size. However, the molecular weight distribution (MWD) is difficult to control in a narrow range for better spinnability. Deep understanding of the polymerization process is needed. In this study, a micro-kinetics model for pitch polymerization is proposed in terms of free radical generation, free radical combination and molecular structure transformation that occur cyclically. The reactions result in molecular size increase and distribution widening. The MWD and average molecular weights are simulated and fitted to the experimental data examined via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The results show that the so-called autocatalysis that makes the MWD widen is acceleration of the reaction speed as molecular size increases since the activation energy of free radical generation decreases. Furthermore, the molecular size of specific solvent insolubility becomes smaller as the reaction progresses. This model can be helpful for the control of the composition of pitch by adjusting the reaction temperature, time and other processes purposefully.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
WATER RESEARCH
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2025
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IF 12.4
Yuanna Zhang,Wenjun Sun,Wenxuan Yin
The widespread application of UV/H 2 O 2 is limited by the empirical operational practices, which can lead to excessive energy, chemical input and the generation of uncontrollable by-products. This study presents a precise regulation approach based on the characteristics of free radical generation/reaction and the chemical transformation of organics, assessed through a pilot experiment. The findings indicated that increasing H 2 O 2 dosage was more effective than increasing UV dose in enhancing •OH generation and pollutant removal. As the H 2 O 2 dosage and UV dose increased, the relative influence of water quality on pollutant removal gradually diminished. Dissolved organic matter (DOM) in the water quality background accounted for the largest proportion of •OH scavenging (76.4 %) and the most complex component. Moreover, changes in operating conditions were accompanied by the uncontrollable production of low-molecular-weight (LMW) DOM. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) revealed the chemical transformation of LMW DOM at the molecular level. Higher H₂O₂ dosages triggered more extensive oxidative degradation, resulting in more complex effluent compositions. Considering treatment efficiency, energy consumption, and effluent product composition, H₂O₂ dosages of 5–10 mg/L and UV doses of 350–450 mJ/cm² were identified as optimal. This research contributes to the efficient purification of organic micropollutants in water using UV/H 2 O 2 technology with low energy consumption, minimal chemical input, and relatively controllable by-products.
研究领域:
环境科学
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水处理技术
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化学工程
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DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
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2025
·
IF 4.7
Jiayu Gu,Mingzhou Wu,Linlin Wang,Fengling Liu,Suhao He,Minrui Ding,Yuye Yao,Neng Tao,Haitao Sha,Zhaobing Guo,Huimin Zhou,Pin Zhou,Pengxiang Qiu
Photocatalyst modification by energy level engineering is crucial for efficient free radical generation. Here, a novel strategy was employed to construct bromine-doped Bi 2 MoO 6 (BMO-Br) followed by an in-situ approach using Cetyltrimethylammonium bromide (CTAB) as the bromine (Br) precursor. The Br doping effectively modulated the energy band, increasing the oxygen vacancy concentration in Bi 2 MoO 6 . The modification significantly enhanced photoinduced charge separation and active free radical generation, leading to superior photocatalytic performance. The photocatalytic bacteriostatic and sulfamethazine (SM) degradation efficiency over BMO-Br-4 reached 100% and 70% within 60 min and 150 min, respectively. This work highlighted a facile yet effective strategy for tailoring the photocatalyst properties, demonstrating promising potential for various photocatalytic applications.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
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2024
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IF 5.5
Bo Chen,Tao Huang,Xiaomeng Geng,Tao Zhou,Youcai Zhao
Background A simple, efficient and cost-efficiency peroxymonosulfate (PMS) oxidation process for organic pollutant removal is expected. This research aims to investigate the feasibility of construction & demolition waste (C&D waste) as recycled material for organic pollutant degradation. Methods C&D waste was novelty introduced into the advanced oxidation process for organic pollutant removal. Taking phenol as the target pollutant, the effects of C&D waste loading, PMS concentration, particle diameter and solution pH were all investigated in this study by a series of batch tests and spectrometry measurements. Significant findings Both the intrinsic oxidation power of PMS and the adsorption of the pretreated C&D waste were negligible under this CDW/PMS system. However, calcinated C&D waste, with calcium silicate generation, enhanced the degradation efficiency of target organic pollutant by promoting the decomposition of PMS to generate • OH and SO 4 •− . Both • OH and SO 4 •− had been detected through the free radicals quenching tests and electron paramagnetic resonance (EPR) spectrometry. Except for high temperature pretreatment, the micro C&D waste after mechanical treatment could also improve the organic pollutant degradation efficiency with a high kinetic rate as a bonus especially for the introduced powder at low doses.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
ULTRASONICS SONOCHEMISTRY
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2024
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IF 8.7
Zhouling Wu,Xiaobin Liu,Huiying Guo,Jie Huang,Guangyu He,Hongyu Chen,Xueyang Liu
It is a challenge to study the nucleation of cavitation bubbles, which critically depends on nanoscale morphological features. Our recent advances in synthesizing colloidal negative-curvature nanoparticles (NGC-NPs) offer a rare opportunity, in comparison to the conventional studies of bulk substrates, where it is difficult to obtain consistent and well-defined surface features. In order to quantitatively assess their effects, we exploit the radical-induced color change of [Fe(SCN) 6 ] 3− , which turned out to be a more convenient method than the bending of AgNWs and the fluorescence-based methods. We show that the NGC-NPs outperform positive-curvature nanoparticles (PSC-NPs) and homogeneous nucleation, in terms of promoting cavitation. The NGC-NPs provide a higher percentage of gas–solid interface, and thus reduces the activation barrier during the critical stage of bubble nucleation. This leads a higher probability of cavitation and transforms more energy from ultrasonication to radical formation and shockwaves.
研究领域:
生物医学工程
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纳米技术
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物理化学
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2017
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IF 6.216
Yong Feng,Hailong Li,Lin Lin,Lingjun Kong,Xiao-yan Li,Deli Wu,Hongying Zhao,Kaimin Shih
The controlled generation of radicals is an effective way to improve the stoichiometric efficiency of oxidants, particularly when treating highly recalcitrant contaminants. In this study, an innovative oxidation system was used to degrade extremely recalcitrant 1,4-dioxane. This system was based on a combination of pyrite, an abundant mineral used as a slow-release source of iron, and peroxymonosulfate (PMS). In addition, other oxidants, including hydrogen peroxide and peroxydisulfate, and their conditions were examined. PMS had the highest degradation performance of the oxidants tested. Near-100% degradation of 1,4-dioxane (50 mg L −1 ) was achieved after 40 min using PMS; the corresponding degradation rates with peroxydisulfate and hydrogen peroxide were around 50% and 15%, respectively. The production of hydroxyl radicals and sulfate radicals by pyrite-activated PMS was confirmed by electron paramagnetic resonance. Neither solid pyrite nor dissolved Fe 2+ or Fe 3+ was directly involved in the degradation. Instead, the Fe 2+ generated from pyrite oxidation activated PMS homogeneously. Quenching tests and the rapid degradation of nitrobenzene show that hydroxyl radicals were the major active species produced by pyrite-PMS. In contrast to the significant scavenging effect of Cl − (3.0 mM) on Co 2+ -PMS, no significant Cl − (≤10 mM) scavenging was observed on pyrite-PMS. These results suggest that the use of pyrite-PMS mitigates the scavenging effects of Fe 2+ and Cl − , and, therefore, may increase the application of iron-based materials and PMS in the water treatment industry.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Jiahao Cui,Xiaolong Gao,Kejing Pang,Wenbing Wu,Mrigendra Kumar Awasthi,Yihua Zhao,Xianqiang Yin
Current single-atom studies in the perdisulfate (PDS) system were focused on transition metals, but researching La-series metals might provide new insights for the efficient utilization of this system. The original structure’s Zn was evaporated at high temperatures, thereby we utilized Zeolitic Imidazolate Frameworks (ZIFs) as a substrate to synthesize a type of La-SACs catalysts. The La single atom in this work was identified to the La-N 4 configuration through La-L3 X-ray edge absorption spectroscopy. Experimental observations in suspension demonstrated that the PDS activation capability of La is on par with, if not superior to, that of transition metals such as Co and Cu. Tetracyclines (10 mg/L) were eliminated within 30 min via La-N-C + PDS systems and the pseudo-first-order was higher than 0.0929 min −1 . The Hydrogen bond between PDS and La-N-C and active electron of d orbital in La atoms had the significant influence on the generation of ROS ( 1 O 2 and •OH). Furthermore, the excellent electron transfer of La-N-C also promoted the activation rate of PDS. The findings of this study indicated that La could play a crucial part in PDS catalyst for degradation of organic pollutes in aquatic environment, providing the new method for exploration of single-atom materials in PDS systems.
研究领域:
环境科学
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催化材料
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化学工程
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DOI
高影响因子
Inorganics
·
2025
·Vol. 13
·期 2
·46
·
IF 3
Mingzhang Zhu,Jiannan Song,Senhua Ke,Yanhong Gu,Lina Bing,Zhenjiang Shen,Wanping Chen
Coating disk-shaped materials on the bottoms of containers has become a highly effective method for tribocatalysis enhancement. Here, the effects of Ti coatings on the tribocatalytic degradation of organic dyes by CdS nanoparticles were systematically studied. For both 50 mg/L rhodamine B (RhB) and 20 mg/L methyl orange (MO) solutions, the tribocatalytic degradation by CdS nanoparticles was dramatically enhanced in Ti-coated beakers compared to as-received glass-bottomed beakers, with the degradation rate constant increased by 4.77 and 5.21 times, respectively. Moreover, for tribocatalytic degradation of MO using CdS, two quite different MO degradation modes were identified between Ti and Al2O3coatings. Electron paramagnetic resonance (EPR) spectroscopy analyses showed that more radicals were generated when CdS nanoparticles rubbed against the Ti coating than against the glass bottom, and boron nitride nanoparticles were employed to verify that the enhancement associated with the Ti coating resulted from the interactions between Ti and CdS. These findings underscore the importance of catalyst and coating material selection in tribocatalytic systems, offering valuable insights for the development of efficient environmental purification technologies.
研究领域:
环境科学
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材料科学
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化学工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2019
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IF 8.355
Yiqun Chen,Mengyu Li,Yang Tong,Zizheng Liu,Liping Fang,Yi Wu,Zheng Fang,Feng Wu,Li-Zhi Huang
We report a process using NiFe 2 O 4 nanocatalyst for the heterogeneous activation of sulfite ions for estriol (E3) oxidation. This NiFe 2 O 4 -sulfite system consisted of NiFe 2 O 4 as an catalyst, sulfite as a reductant, O 2 as an oxidant, and oxysulfur radicals (SO 3 − , SO 4 − and SO 5 − ) and hydroxyl radicals (HO ) as generated radicals. The experimental conditions for E3 removal were investigated, including the initial pH values, dissolved oxygen concentration, and NiFe 2 O 4 and sulfite ion dosages. The initial pH has a significant influence on the catalytic performance, and approximately 87.6% of E3 could be removed at pH 9.0. NiFe 2 O 4 nanocatalyst was characterized by high resolution and field emission transmission electron microscopy, X-ray diffractometry, and X-ray photoelectron spectroscopy. The catalytic reactivity and stability of the NiFe 2 O 4 nanocatalyst were investigated by consecutive repeated runs. Radicals generated in this NiFe 2 O 4 -sulfite system were identified via radical-scavenging and electron spin resonance experiments. SO 5 − was identified as major oxidative radicals for E3 removal, which is quite different from the previous studies on sulfite activation . The generation of >SO 3 2− -Ni(II)-OH on NiFe 2 O 4 surface played a critical role in sulfite auto-oxidation. Our results supplemented the mechanism of the sulfate radical generation with sulfite ion as a source.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
CHEMOSPHERE
·
2023
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IF 8.8
Zilong Zhao,Shuyu Qi,Jianli Zhou,Yatao Ren,Kaiyun Zheng,Jin Zhang,Wenyi Dong,Hongjie Wang
To enhance the polarization distribution of electron cloud density on the catalyst surface, we have introduced a novel bimetallic-substituted dual-reaction center (DRC) catalyst (FeCo-γ-Al 2 O 3 ) comprising iron (Fe) and cobalt (Co) for the decomplexation and mineralization of heavy metal complex Ni-EDTA in this study. Compared to the catalysts doped solely with Fe or Co, the bimetal-doped catalyst offered several advantages, including enhanced electron cloud polarization distribution, additional electron transfer pathway, and improved capacity of free radical generation. Through DFT calculations and EPR tests, we have elucidated the influences of the catalyst's adsorption toward Ni-EDTA and its decomplexation products on the electron transfer between the pollutant and the catalyst. The competition between the pollutants and H 2 O 2 affects the generation of free radicals in both electron-rich Fe and Co centers as well as electron-deficient Al center. Building on these findings, we have proposed a plausible removal mechanism of Ni-EDTA using the heterogeneous Fenton-like catalyst FeCo-γ-Al 2 O 3 . This study sheds light on the potential of FeCo-γ-Al 2 O 3 as a DRC catalyst and emphasizes the significance of pollutant characteristics in determining the catalyst's performance.
研究领域:
环境科学
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材料科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）