Query: “BiOCl” and "C3N4"

Candidate papers:

abstract: The interfacial charge transfer still limits the photoactivity of artificial Z scheme photocatalysts although they showed complementary light absorption and a strong photoredox ability. In this study, layered metallene is designed as an efficient electron mediator for constructing a C3N4/bismuthene/BiOCl 2D/2D/2D Z scheme system. This bismuthene serves as a bridge processing superior charge conductibility, abundant metal semiconductor contact sites, and the shortened charge diffusion distance, enhancing the photocatalytic CO2 reduction reaction activity and stability. Density functional theory calculations show that the bismuthene creates a built in electric field and congregates interfacial electrons, which is confirmed by the stable and consistent emission of the ultrafast transient absorption spectra. This work gives new insight into the interface design of Z scheme photocatalysts by selecting a novel metallene electron mediator.
author_names: Dan Zhang

Xiaoqiang Cui

Lulu Liu

Yanchao Xu

Jianhui Han
title: 2D Bismuthene Metal Electron Mediator Engineering Super Interfacial Charge Transfer for Efficient Photocatalytic Reduction of Carbon Dioxide.
venue: ACS applied materials interfaces
year: 2021

abstract: Abstract Designing hetero junction photo catalysts with high separation efficiency of photo generated charge carriers has been recognized as an optimistic route to water purification and hydrogen generation. The interfacial interaction and band potential fluctuation in forming hetero junction play important roles in photo catalytic activity. In this work, a series of highly active layer structured g C3N4/BiOCl (C3N4/BOC) hetero junction have been successfully synthesized through a two step calcination hydrothermal method. The hetero junction photo catalysts exhibit 8.15 times higher degradation rate for Rhodamine B (RhB) and 6.97 times higher H2 evolution rate than those of pristine g C3N4. For comprehensively understand the charge transfer mechanism, experimental characterization and theoretical Density functional theory (DFT) calculations are adopted in the single phase semiconductor and hetero junction system. The superior photo induced electron holes separation ability and band potential fluctuation of present photo catalysts are confirmed. This work provides insightful understanding for the formation mechanism of hetero junction photo catalysts.
author_names: Ruoyu Zhang

Siying Niu

Jinmeng Xiang

Jiming Zheng

Zhenyi Jiang

Chongfeng Guo
title: Band potential fluctuation in C3N4/BiOCl hetero junction for boosting photo catalytic activity
year: 2021

abstract: Abstract Photocatalytic degradation of noxious pollutants is an efficacious approach to combat water pollution. The heterojunction photocatalysts having low band gap and recombination rate have immense significance in this respect. Herein, a series of composites (various weight ratios of g C3N4@BiOCl) are constructed by conglomerating g C3N4 nanosheets with BiOCl nanoplates by a wet chemical process. XRD, XPS, EDX, and TGA analysis verified the successful formation, uniform distribution, and thermal stability of the catalysts. FESEM and HRTEM images exhibited that BiOCl platelets are well covered with g C3N4 nanosheets. The UV DRS and PL spectroscopy confirmed that the hybrid had a low bandgap and a low recombination rate facilitating charge separation. BET assay revealed that 3:1 g C3N4@BiOCl had the highest surface area (107 m2/g) with mesopores. To assess the catalyst's photocatalytic performance, MB and IC were degraded in natural sunlight. Kinetic studies showed that the 3:1 g C3N4@BiOCl hybrid manifested the best performance (degrading 94.8% of MB and 73.4% of IC) and rate constant (0.0301 min 1 and 0.0085 min 1 for MB and IC, respectively) An effect of pH and catalyst concentration on the photodegradation was also investigated. Trapping experiments revealed that O2* was the major reactive species in the photodegradation mechanism. The successful IC degradation confirmed the occurrence of indirect photocatalysis. The catalyst was reused for MB degradation showing 75% efficiency even after 5 sequential cycles. Considering the simplistic preparation and excellent properties, g C3N4@BiOCl can be used as a promising and competitive solar light driven photocatalyst for environmental remediation.
author_names: Aayushi Kundu

Surbhi Sharma

Soumen Basu
title: Modulated BiOCl nanoplates with porous g C3N4 nanosheets for photocatalytic degradation of color/colorless pollutants in natural sunlight
venue: Journal of Physics and Chemistry of Solids
year: 2021

abstract: BiOCl/g C3N4 (BC) heterojunctions were constructed successfully through a novel in situ hydrolysis method by taking metallic Bi nanospheres as Bi source. The TEM and HRTEM images showed the heterogeneous nanostructures at the interface between BiOCl and g C3N4. The combination of BiOCl and g C3N4 enlarged the light adsorption range of the BC heterojunctions, which extended to visible region. Besides, the contact of the two semiconductors at the heterointerfaces improved the separation efficiency of photoinduced charge carriers, thus endowing the BC samples with superior visible light driven (VLD) photocatalytic performance in degrading organic pollutants. Notably, the BC12% sample exhibited the optimized photocatalytic activity in which 97.3% of RhB was decomposed within 30 min, achieving 13.87 and 4.26 times improvement than the bare BiOCl and pristine g C3N4, respectively. Moreover, the trapping experiments revealed that .O2 and h+ were the dominant active species during the degradation processes of RhB. Meanwhile, the possible degradation pathway of RhB was proposed on the basis of the intermediate products detected by LC MS, and the appearance photocatalytic mechanisms were also discussed in detail. As an original strategy to obtain samples with highly dispersed heterointerface, this work provides a facile route for the surface modification of g C3N4 via a facile hydrolysis process of metallic particles to form heterostructures and very promising for practical application.
author_names: Zikang Zeng

Kai Li

Tao Yuan

Yujun Liang

Jian Yang

Guie Yang

Kun Wang

Zhuoran Xiong
title: Facile synthesis of BiOCl/g C3N4 heterojunction via in situ hydrolysis of Bi nanospheres: a high efficiency visible light driven photocatalyst
venue: Journal of Materials Science: Materials in Electronics
year: 2021

abstract: Abstract Advanced analytical instrumentations and improved analytical techniques have paved the way to detect many chemicals in natural waters. These chemicals, collectively termed emerging contaminants (ECs) include drugs, disinfectants, plasticizers, detergents, surfactants, pesticides, dyes, paints, preservatives, food additives, and personal care products released into the environment by chemical and pharmaceutical industries, hospitals, households, wastewater treatment plants, and land runoff. The effectiveness of EC removal by traditional methods, that is, biodegradation, coagulation, and sedimentation, is often low or very low. In recent years, advanced oxidation processes (AOP) such as photocatalysis, photo Fenton, and ozonation, have been effectively used to remove these contaminants. Among these AOPs, solar photocatalysis has drawn major attention in treating ECs due to its low cost and ease of operation. Solar photocatalysis utilizes the absorption of sunlight by the semiconductor catalyst for its activation. Upon irradiation with light (photon energy) greater than or equal to its bandgap energy, the semiconductor photocatalyst generates an electron (e and hole (h+ pair (EHP) These photogenerated EHPs would promote different redox reactions, facilitating pollutant degradation. The semiconductor photocatalysts used in the photocatalysis process include TiO2, ZnO, WO3, Cds, Fe2O3, Cu2O, CdSe, etc. However, the higher bandgap energy of these catalysts necessitates ultraviolet irradiation for the excitation. On the other hand, to reduce the bandgap energy and to cause visible light (sunlight) excitation, several modifications are carried out such as metal/nonmetal doping, coupling, structural modification, and noble metal deposition on the surface. Some of the modified catalysts such as TiO2/Cu2O, Bi2O3/g C3N4, Ag/TiO2, Au/TiO2, Pt/TiO2, C TiO2, N TiO2, and BiOCl/Bi24O31Cl10 showed good efficiency in pollutant degradation by solar photocatalysis. Solar photocatalysis has been successfully employed for EC degradation from wastewater. For example, TiO2/Cu2O and WO3 catalysts resulted in 100% and 99.39% degradation of the pharmaceuticals sulfamethazine and amoxicillin, respectively, from wastewater within 3 h. However, the solar photocatalytic performance depends on different parameters such as pH, oxidant dosage, and natural organic matter in wastewater. This study will summarize the solar photocatalytic treatment employed for the removal of ECs from wastewater with an emphasis on the catalyst modification.
author_names: Venkatesan Prashanth

P K Jayasree

P R Rajput

Neelancherry Remya
title: Solar photocatalysis and its application for emerging contaminant removal from wastewater
year: 2021

abstract: In this work, g C3N4 x/BiOCl/WO2.92 heterojunction with "N O" vacancies was prepared using NaBiO3 and WCl6 as raw materials and non metal plasma of WO2.92 grew in situ on the surface of BiOCl, resulting in the enhanced photocatalytic NO deep oxidation. XPS tests and DFT calculation indicated the formation of internal electric fields from g C3N4 x to BiOCl, BiOCl to WO2.92, which induced the transition from II II type to double Z scheme hetero structure. High separation efficiency, prolong lifetime and strong redox ability of photo generated electron hole pairs were simultaneously achieved due to the charge capture effect of defects and double Z scheme mechanism. Therefore, g C3N4 x/BiOCl/WO2.92 exhibited the significantly increased NO removal rates from 21.17% (BiOCl/WO2.92) and 36.52% (g C3N4 x) to 68.70% and the main oxidation product of NO was NO3 This study revealed that the carrier dynamics of heterojunction photocatalysts could be optimized by the synergistic effect of defects and internal electric fields to achieve photocatalytic NO deep oxidization.
author_names: Mozhen Wang

Guoqiang Tan

Shuaijun Feng

Mingyue Dang

Bixin Zhang

Huijun Ren

Long Lv

Ao Xia

Wenlong Liu

Yun Liu
title: Defects and internal electric fields synergistically optimized g C3N4 x/BiOCl/WO2.92 heterojunction for photocatalytic NO deep oxidation.
venue: Journal of hazardous materials
year: 2020

abstract: Abstract A Z scheme of 2D/2D BiOCl/g C3N4 nanosheet like composite was prepared by hydrothermal method. The properties of prepared samples were well tested by XRD, FT IR, PL, EIS, SEM equipped with EDS, XPS, UV Vis DRS analysis. After the BiOCl nanosheets anchored on g C3N4 nanosheets, the BiOCl/g C3N4 3 composite exhibited a remarkable photocatalytic efficiency and antimicrobial activity for tetracycline (TC) About 97.1% of TC degraded within 60 min and the TOC removal rate of TC reached to 76.3% in 180 min. Moreover, the E.coli reduction of antimicrobial activity reached to 96.5% after 40 min illumination. Those excellent photocatalytic efficiency of BiOCl/g C3N4 3 composite was contribution of the rapid charge transfer in Z scheme system. Finally, 4 cycles of photocatalytic experiments revealed an excellent stability and reusability of BiOCl/g C3N4 3 composite.
author_names: Yuwei Sun

Xin Qi

Qiang Tang

Baixiang Ren
title: Hydrothermal synthesis of 2D/2D BiOCl/g C3N4 Z scheme: For TC degradation and antimicrobial activity evaluation
year: 2020

abstract: Abstract In this paper, a novel heterojunction material was synthesized of C3N4 via doping with p deficient conjugated pyridine ring molecules (2,6 diaminopyridine) and BiOCl by ultrasound assisted method. First, doping C3N4 with 2,6 diaminopyridine can reduce the structural integrity and orderliness of C3N4, and reduce the number of structural fragments, Which makes C3N4 have more reactive sites. And then BiOCl nanosheets were grown on the surface of the modified C3N4 nanosheets to obtain a new heterojunction material composed of modified C3N4 doped with p deficient pyridine ring molecules and BiOCl by the co precipitation method. At last, the degradation of methyl orange (MO) by BiOCl, C3N4, modified C3N4 doped with 2,6 diaminopyridine, and a series of C3N4 doped with 2,6 diaminopyridine and BiOCl composite heterojunction materials under visible light was studied. X ray diffraction (XRD) scanning electron microscope (SEM) high resolution transmission electron microscopy (HRTEM) X ray photoelectron spectroscopy (XPS) Brunauer Emmett Teller (BET) ultraviolet visible diffuse reflection (UV Vis DRS) and transient photocurrent densities, and electrochemical impedance spectroscopy (EIS) were used to analyze the structure, morphology, and photogenerated charge transfer characteristics of samples. The experimental results show that the new heterojunction composite materials has better photocatalytic activity compared with pure BiOCl, C3N4, and modified C3N4 doped with 2,6 diaminopyridine. In addition, the degradation performance of methyl orange with different mass ratios of composite materials is also different. When the mass ratio of C3N4 doped with 2,6 diaminopyridine to BiOCl is 1:2, The composite material exhibits the best photocatalytic performance, which may be related to the synergistic effect of the modified C3N4 doped with 2,6 diaminopyridine and BiOCl. Based on the band structure and active species experiments, the reasons for the enhanced photocatalytic activity are discussed, and the possible degradation mechanisms are proposed. The research in this paper provides an effective new way to construct new heterojunction materials.
author_names: Wei Yang

Xinyao Shan

Ying Chen

Yanhua Gao
title: Enhanced photocatalytic performance of C3N4 via doping with p deficient conjugated pyridine ring and BiOCl composite heterogeneous materials
year: 2020

abstract: Abstract Bismuth oxychloride (BiOCl) limited by a wide band gap, makes it poor perform in visible light driven photodegradation. The novel semiconductor composites of BiOCl/g C3N4@UiO 66 composites were first prepared through the facile solvothermal approach. BiOCl/g C3N4@UiO 66 photocatalysts were characterized and BiOCl nanoplates and g C3N4 nanosheets were successful constructed and further decorated on the surface with UiO 66. In comparison with the binary composites and the pure materials, BiOCl/g C3N4@UiO 66 exhibits the higher RhB photocatalytic degradation under visible light irradiation. The enhanced photocatalytic activity of BiOCl/g C3N4@UiO 66 composites can be attributed to the lower recombination probability of electron hole pair of the heterojunction, increased surface area for RhB adsorption accomplished with photodegradation process.
author_names: Yu Zhu

Mengying Zhu

Hua Lv

Su Rui Zhao

Qiyuan Zhang

Wen Kun Zhu

Bingdong Li
title: Coating BiOCl@g C3N4 nanocomposite with a metal organic framework: Enhanced visible light photocatalytic activities
year: 2020

abstract: In this work, fibrous TiO2@g C3N4 nanocomposites (FTGCNCs) were used for dispersive micro solid phase extraction of Co and Ni prior to their determination by inductively coupled plasma mass spectrometry. As a new adsorbent, the surface on FTGCNCs have rich functional groups such as NH2, NH and =N which can selectively adsorb target ions. The adsorption behaviors of Co and Ni on FTGCNCs were investigated. The results indicated that the analytes were quantitatively retained on FTGCNCs in the pH range of 5.0 8.0 and eluted completely with 1.0 mL of 0.5 mol L HNO3 solution. The main factors influencing the preconcentration and determination of the analytes were investigated in detail, including the pH of the sample solution, dosage of adsorbent, extraction/elution time, elution parameters and sample volumes. Under the optimum conditions, the detection limits of this method were 0.12 pg mL and 1.34 pg mL for Co and Ni, respectively. The relative standard deviations were 3.9% for Co and 4.8% for Ni (n=9, c=1.0 ng mL) This method was used for the determination of trace/ultra trace Co and Ni in environmental water samples with satisfactory results. In order to verify this method, three certified reference materials of stream sediment, human hair and mussel were analyzed using the proposed method, and the determined results were in agreement with the certified values.
author_names: Shizhong Chen

Yuxiu Liu

Juntao Yan

Chunlei Wang

Deng-bo Lu
title: Dispersive Micro solid Phase Extraction with Fibrous TiO2@g C3N4 Nanocomposites Coupled with ICP MS for the Determination of Cobalt and Nickel in Environmental and Biological Samples
year: 2020