摘要：
In this study, we systematically investigated the degradation efficiency and the degradation mechanism of atrazine in the presence of ascorbic acid at different pH values. Although atrazine could be degraded by ascorbic acid in a wide pH range from 4 to 12, its degradation under either acidic (pH <= 4) or alkaline (pH >= 12) condition was more efficient than under neutral condition (pH = 7). This pH dependent atrazine degradation was related to the reactive characteristic of atrazine and the reductive activity of ascorbic acid. The ascorbic acid induced atrazine degradation pathways at different pH were investigated by comparing the atrazine degradation intermediates with liquid chromatography-mass spectrometry, high performance liquid chromatography and ion chromatography. It was found that more products were detected in presence of ascorbic acid at alkaline condition. The appearance of chloride ions confirmed the dechlorination of atrazine by ascorbic acid in the absence of molecular oxygen, while its dechlorination efficiency reached highest at pH 12. These results can shed light on the application of AA for the organic pollutant remediation. (C) 2016 Elsevier B.V. All rights reserved.
作者机构：
[Zhang, Lizhi; Li, Jie; Cai, Lejuan; Shang, Jian] Cent China Normal Univ, Coll Chem, Inst Environm Chem, Key Lab Pesticide & Chem Biol,Minist Educ, Wuhan 430079, Peoples R China.;[Li, Jie; Yu, Ying] Cent China Normal Univ, Coll Phys Sci & Technol, Inst Nanosci & Nanotechnol, Wuhan 430079, Peoples R China.
通讯机构：
[Zhang, Lizhi] C;Cent China Normal Univ, Coll Chem, Inst Environm Chem, Key Lab Pesticide & Chem Biol,Minist Educ, Wuhan 430079, Peoples R China.
关键词：
bulk-charge separation;doping;internal electric field;photocatalysis;water oxidation
摘要：
A study was conducted to demonstrate giant enhancement of internal electric field (IEF) boosting bulk charge separation (BCS) for photocatalysis. The study synthesized C-doped Bi3O4 Cl nanosheets with reported carbon doping strategy. These nanosheets had {001} facets on their top and bottom, {110} facets on their four lateral surfaces, and {010} facets at their four corners. Their elemental mapping images and time-resolved X-ray photoelectron spectroscopy revealed the homogeneous distribution of carbon dopants within Bi3O4.
通讯机构：
[Ai, Zhihui] C;Cent China Normal Univ, Inst Environm Chem, Key Lab Pesticide & Chem Biol, Minist Educ, Wuhan 430079, Peoples R China.
关键词：
Ascorbic acid;Ferrous ions;Oxygen activation;ROS;Rhodamine B
摘要：
Molecular oxygen activation by ferrous ions (Fe(II)) in aqueous solution could generate reactive oxygen species (ROS) with high oxidation potential via reaction between Fe(II) and oxygen molecules (Fe(II)/air), however, ROS yielded in the Fe(II)/air process is insufficient for removal of organic pollutants due to the irreversible ferric ions (Fe(III)) accumulation. In this study, we demonstrate that ascorbic acid (AA) could enhance ROS generation via oxygen activation by ferrous irons (AA/Fe(II)/air) and thus improve the degradation of rhodamine (RhB) significantly. It was found that the first-order aerobic degradation rate of RhB in the AA/Fe(II)/air process in the presence of ascorbic acid is more than 4 times that of the Fe(II)/Air system without adding ascorbic acid. The presence of ascorbic acid could relieve the accumulation of Fe(III) by reductive accelerating the Fe(ill)/Fe(II) cycles, as well as lower the redox potential of Fe(III)/Fe(II) through chelating effect, leading to enhanced ROS generation for promoting RhB degradation. This study not only sheds light on the effect of ascorbic acid on aerobic Fe(II) oxidation, but also provides a green method for effective remediation of organic pollutants. (C) 2016 Elsevier B.V. All rights reserved.
作者机构：
[Zhang, Lizhi; Li, Jie; Zhan, Guangming] Cent China Normal Univ, Coll Chem, Inst Environm Chem, Key Lab Pesticide & Chem Biol,Minist Educ, Wuhan 430079, Peoples R China.;[Li, Jie; Yu, Ying] Cent China Normal Univ, Coll Phys Sci & Technol, Inst Nanoscience & Nanotechnol, Wuhan 430079, Peoples R China.
通讯机构：
[Zhang, Lizhi] C;Cent China Normal Univ, Coll Chem, Inst Environm Chem, Key Lab Pesticide & Chem Biol,Minist Educ, Wuhan 430079, Peoples R China.
摘要：
Although photocatalytic hydrogen evolution (PHE) is ideal for solar-to-fuel conversion, it remains challenging to construct a highly efficient PHE system by steering the charge flow in a precise manner. Here we tackle this challenge by assembling 1T MoS2 monolayers selectively and chemically onto (Bi12O17) end-faces of Bi12O17Cl2 monolayers to craft two-dimensional (2D) Janus (Cl2)-(Bi12O17)-(MoS2) bilayer junctions, a new 2D motif different from van der Waals heterostructure. Electrons and holes from visible light-irradiated Bi12O17Cl2 are directionally separated by the internal electric field to (Bi12O17) and (Cl2) end-faces, respectively. The separated electrons can further migrate to MoS2 via Bi-S bonds formed between (Bi12O17) and MoS2 monolayers. This atomic-level directional charge separation endows the Janus bilayers with ultralong carrier lifetime of 3,446 ns and hence a superior visible-light PHE rate of 33 mmol h-1 g-1. Our delineated Janus bilayer junctions on the basis of the oriented assembly of monolayers presents a new design concept to effectively steer the charge flow for PHE.
作者机构：
Key laboratory of Pesticide & Chemical Biology of Ministry of Education,Institution of Environmental Chemistry,College of Chemistry,Central China Normal University,Wuhan 430079,P.R.China
摘要：
It is well known that nitrogen oxides are major atmospheric pollutants threatening human health. Although Photo-assisted selective catalytic reduction of nitric oxide（NO） as a novel approach has been studied a lot over the past years and the removal rate of NO was raised relatively high by choosing specific catalyst like Ti O2 etc, the mechanism of the NO activation over the photocatalyst is hardly reported. Our group has already reported that Bi OBr nanoplate microsphere could remove NO indoor air under visible light irradiation, but the conduction band of Bi OBr is too positive and the construction is not stable during the course of the photocatalytic NO removal process. We considered that Bi3O4 Br nanosheet might be a better choice owing to its strong internal electric field and great stability. Inspired by the fact that oxygen vacancy can activated molecular oxygen, even nitrogen efficiently, we induce OVs on Bi3O4 Br and selected this OVs-contained Bi3O4 Br as the model photocatalysis to explore the reaction pathway and activation mechanism of NO. Our experimental results proved OVs-contained Bi3O4 Br was a high-performance NO removal photocatalyst, and the interaction between the OV and NO was investigated by DFT（Density Functional Theory） theoretic calculations based on first principles.
作者机构：
College of Science, Huazhong Agricultural University;Department of Science & Environmental Studies and Centre for Education in Environmental Sustainability, the Hong Kong Institute of Education;Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental Chemistry, College of Chemistry,Central China Normal University
摘要：
In this study, we demonstrated that the reactive species generation of Bi2 MoO6 under visible light can be regulated by Bi self-doping via a simple soft-chemical method. Density functional theory calculations and systematical characterization results revealed that Bi self-doping could not only promote the separation and transfer of photogenerated electron-hole pairs of Bi2MoO6 but also alter the position of valence and conduction band without changing its preferential crystal orientations, morphology, visible light absorption as well as band gap energy. The photocatalytic removal of NO and products determination revealed that the enhanced generation of superoxide could improve the oxidation of NO to NO2 while ·OH and photogenerated holes mainly contributed to the further oxidation of NO2 to NO3-. Photostability and NO absorbtion tests demonstrated that NO3- on the surface of catalysts occupied the NO absorption sites and caused the deactivation of catalysts. This study provides new insight into the different effects of photogenerated reactive species on NO removal and sheds light on the design of highly efficient visible light-driven photocatalysts for NO removal.
作者机构：
Key Laboratory of Pesticide & Chemical Biology of Ministry of Education,Institute of Environmental Chemistry,College of Chemistry,Central China Normal University,Wuhan 430079,P. R. China
关键词：
removal of nitrogen oxide;Bi OX;theoretical calculation;photocatalytic oxidation
摘要：
Nitrogen oxide（NOx） which is an important secondary aerosol precursor and involved in the formation of photochemical smog, has proved as an important family of air polluting chemical compounds. NO and NO2 with lone electron pair are endowed NOx with acidic character and active redox properties. Photocatalytic oxidation of NOx is very promising for the sustainable development, but the efficiency of the state-of-the-art semiconductor photocatalytic oxidation of NOx is far from satisfactory. In this study, theoretical calculation was first used to calculate band structure, analyze valence and conduction bands composition and position and electronic structure. Optimizing the competitive adsorption process of NO, NO2, O2 and H2 O on the Bi OX（X=Cl,Br,I） by using Material Studio. Combined with theoretical calculation, highly efficient and stable Bi OX photocatalysts material for removal of NOx were synthesized. Strategies such as oxygen defects, crystal face exposed, nonmetallic doping, exfoliation…were used to regulate the composition and band structure of Bi OX.Abundant highly oxidizing species and orientation transformation of NO2 to NO3- were achieved. This work demonstrates a efficient synthesis method for Bi OX sample combined with the associated high activity and durable photocatalytic performance could provide an attractive and feasible technology for air cleaning.
作者机构：
[Xing Ding; Hao chen] College of Science,Huazhong Agricultural University,Wuhan 430070,China;[Lizhi Zhang] Key Laboratory of Pesticide & Chemical Biology of Ministry of Education,Institute of Environmental Chemistry,College of Chemistry,Central China Normal University,Wuhan 430079,China
会议名称：
第十八届中国科协年会
会议时间：
2016-9-1
会议地点：
西安
会议主办单位：
中国科协;陕西省人民政府
关键词：
Boron;Nitrogen;Co-doped;TiO2;Photocatalysis
摘要：
In this study,we demonstrate that B-N-codoped TiO2 photocatalyst possesses superior photocatalytic activity to the single element doped TiO2 products on the degradation of NO in a flow system under both simulated solar-light and visible light irradiation.
