片状石墨相氮化碳的制备及光催化性能研究

以三聚氰胺为前驱体,采用高温煅烧法、水热法预处理法、氨基修饰法以及氮气二次煅烧(热剥离法)制备g-C₃N₄,并对样品进行了结构表征与分析,并进行了光催化性能及稳定性测试。结果表明：四种制备方法对样品的光催化活性有显著的影响,热剥离法制备的样品有较好的光催化性能,氨基改性法制备的样品具有较好的稳定性能,可以多次重复使用。     

石墨相氮化碳材料及其光催化应用

石墨相氮化碳具有独特的电子能带结构和优异的化学稳定性,作为一种不含金属成分的新型可见光光催化剂,在光催化领域有着广泛的应用前景。介绍了近年来石墨相氮化碳的研究现状,重点探讨其合成方法、结构特性和其相关的衍生物以及在光催化中的应用。     

片层氮化碳/Ti3C2的制备及其光催化产氢

通过水热法将Ti3 C2制备成米粒状,并将之负载于氮化碳表面,得到氮化碳/Ti3 C2复合材料.通过场发射扫描电镜及其Mapping元素分析发现,Ti3C2比较均匀地分散在氮化碳表面.并且该复合材料在可见光激发下具有良好的产氢活性(54.6μmol/h),是未改性氮化碳(18.1μmol/h)的3.01倍.此外,该复合...     

聚吡咯/石墨相氮化碳光催化材料的制备及其铀降解性能研究

为了提高g-C_3N_4的光催化性能,通过原位聚合法制备了PPy/g-C_3N_4复合材料。通过SEM、XRD、BET和FTIR等表征手段研究PPy/g-C_3N_4的微观形貌、化学组成以及光催化降解铀的性能。结果表明,PPy抑制了g-C_3N_4晶粒的生长,提高了g-C_3N_4的比表面积。在降解时间60 min,pH=5,U(VI)初始浓度5 mg/L,光催化剂投加量200 mg/L的条件下,g-C_3N_4和PPy/g-C_3N_4复合材料对U(VI)的降解率分别为83.11%和96.20%。重复使用3次后,PPy/g-C_3N_4对U(VI)的降解率仍达92.4%。     

聚吡咯/石墨相氮化碳光催化材料的制备及其铀降解性能研究

为了提高g-C3N4的光催化性能,通过原位聚合法制备了PPy/g-C3N4复合材料.通过SEM、XRD、BET和FTIR等表征手段研究PPy/g-C3 N4的微观形貌、化学组成以及光催化降解铀的性能.结果表明,PPy抑制了g-C3 N4晶粒的生长,提高了g-C3N4的比表面积.在降解时间60 min,pH=5,U(VI...     

石墨相氮化碳纳米片的可控制备及光催化性能EI北大核心CSCD

通过调控前驱体三聚氰胺和尿素比例采用热聚合法得到一系列厚度可控的石墨相氮化碳(g-C_(3)N_(4))纳米片。采用X射线粉末衍射、扫描电镜、原子力显微镜、比表面积测试、紫外可见光谱和荧光光谱等手段对纳米片的结构和性能进行了表征,并探讨了其光催化降解罗丹明B(Rh B)的性能。结果表明:当三聚氰胺和尿素比例为1:8时g-C_(3)N_(4)最薄(1:8-CN),厚度仅为3.518 nm,同时1:8-CN的比表面积是以三聚氰胺为原料制备的g-C_(3)N_(4)(M-CN)的7倍。光电学分析表明,1:8-CN具有更高的光生载流子分离效率。在可见光照射下,1:8-CN对Rh B的光催化降解率可以达到96.2%,是M-CN的1.9倍。1:8-CN光催化降解Rh B的反应机理表现为:光生电子-空穴对分离产生的电子与O2结合生成·O_(2)^(-),·O_(2)^(-)将Rh B氧化生成CO2和H2O,空穴几乎不参与反应。     

甲酸铵处理对氮化碳光催化性能的影响

石墨相氮化碳(g-C₃N₄)作为环境友好型材料在半导体光催化领域广受关注,然而未经改性的g-C₃N₄光吸收范围窄,仅能对太阳光谱中蓝紫光区响应,同时比表面积小,且光生载流子分离及迁移速率慢,导致光催化性能不佳。本文以g-C₃N₄为研究对象,将甲酸铵(NH₄HCO₂)和硫脲(CH₄N₂S)按不同比例混合,在马弗炉中520℃下高温煅烧(升温4 h保温2 h),制得C元素掺杂的石墨相氮化碳。g-C₃N₄中掺杂C元素可提高光吸收能力、调整电荷密度、促进光生载流子解离,从而显著提高其光催化效率。通过降解模拟污染物罗丹明B(RhB)发现,当n(CH₄N₂S)∶n(NH₄HCO₂)=1∶0.04时表现出最好的光催化活性,其对罗丹明B的降解效率几乎能达到1...     

石墨相氮化碳的光催化应用研究

光催化技术利用太阳能激发出半导体的氧化还原活性,是一项环境友好型技术。石墨相碳氮碳(g-C₃N₄)是一种非金属半导体聚合物,它在各类光催化研究中表现出优异的光催化活性。总结了光催化技术在减缓化石能源危机和解决环境污染方面的应用,论述了g-C₃N₄在各技术中的光催化反应原理,并扼要分析了g-C₃N₄在光催化领域的发展趋势。     

磷、钴共掺杂氮化碳对染料废水的处理研究

通过热缩聚尿素的方法制备了石墨相氮化碳和P、Co共掺杂的石墨相氮化碳催化剂,研究其在可见光照射下,对碱性品红、罗丹明B、甲基橙、直接枣红和亚甲基蓝染料的催化降解效果。结果表明,改性后的催化剂,对5种染料废水的催化效果均优于未改性的催化剂,光照120 min,罗丹明B和亚甲基蓝的降解率较高,分别为95.15%和92.69%,碱性品红、甲基橙和直接枣红的降解率较低,分别为49.37%,56.68%,60.69%。采用多种仪器对催化剂进行了表征,发现P、Co共掺杂催化剂催化效果提升的原因是其对可见光吸收增强,光生电子-空穴对的分离率增加。     

Development of g-C3N4/ZnO nanocomposite as a novel,highly effective and durable photocatalytic antibacterial coating for cotton fabric

Photocatalytic antibacterial coats are considered among the best solutions to bacterial contamination of fabrics, with the drawback of reduced efficacy after continued use and washing. In the present study, the g-C₃N₄/ZnO (CNZ) nanocomposite has been introduced as a novel cotton fabric coating, with high durability, and CNZ nanopowders were synthesized using a two-step thermal synthesis process and directly coated onto cotton fabric using the sonication technique. The synthesized nanoparticles (NPs) were examined using X-ray diffraction (XRD), UV–visible spectroscopy, photoluminescence (PL), Brunauer-Emmett-Teller (BET), and Fourier transform infrared (FTIR) analyzes. Besides, the SEM analysis confirmed the successful deposition of NPs on cotton fabric. The photodegradation of methylene blue (MB) stain was assessed as a functional test for the photocatalytic effectiveness of the coated fabric, then its antibacterial properties were evaluated under visible light, by direct contact with bacterial suspensions and culturing. The results revealed that the CNZ-coated cotton fabric containing 30% ZnO (CNZ-30) has significant photocatalytic antibacterial activity against both Escherichia coli (gram-negative), and Staphylococcus aureus (gram-positive) bacteria. The bacterial reduction rate of CNZ-30 coated fabric for both E. coli and S. aureus was above 98%, even after 18 washing cycles. This excellent performance is attributed to the effective coupling of ZnO with g-C₃N₄, improved light absorption, and reduced e⁻/h⁺ pair recombination rates. This study novel coating method can offer an environmentally friendly, cost-effective, and simple process to manufacture hybrid CNZ antibacterial cotton in the textile industry.     

VO@g?C3N4-T可见光催化苯羟基化制苯酚

以尿素和乙酰丙酮氧钒为原料制备了钒氧化合物络合在纳米薄片石墨化氮化碳上的光催化剂(VO@g?C3N4-T),并与石墨化氮化碳（g?C3N4）、钒氧化合物负载在石墨化氮化碳上催化剂（VO/g?C3N4）进行了对比。采用N2吸附、X射线衍射光谱(XRD)、扫描电镜(SEM)、能谱（EDS）、电感耦合等离子体-原子发射光谱(ICP-AES)分析手段对制备的催化剂进行了表征。考察了所得催化剂可见光催化苯羟基化制 苯酚的性能。结果表明,高比表面积、纳米薄片状的VO@g?C3N4-T催化剂具有合适的带差,导致可见光催化苯的C-H键活化及羟基化具有较好的催化性能,转化率和选择性可以达到98.4%、91.1%。由于石墨化氮化碳和钒具有较强的相互作用,这减少了钒的溶脱,所以该催化剂具有很好的可重复使用性,连续使用五次后,苯的转化率和苯酚的选择性没有明显降低。     

Synthesis of dynamic g-C3N4/Fe@ZnO nanocomposites for environmental remediation applications

An effective g-C₃N₄/Fe@ZnO heterostructured photocatalyst was synthesized by a simple chemical co-precipitation method and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and ultraviolet–visible spectroscopy. Transmission electron microscopy revealed that 7-8 nm-sized 1%Fe@ZnO nanoparticles were evenly distributed on g-C₃N₄ nanosheets to form a hybrid composite. The photocatalytic effectiveness of the composites was assessed against methylene blue dye, and it was found that the 50%g-C₃N₄/Fe@ZnO photocatalyst was more efficient in harvesting solar energy to degrade dye than the ZnO, 1%Fe@ZnO, g-C₃N₄, g-C₃N₄/ZnO and (10, 25, 40, 60 & 75 wt%) g-C₃N₄/Fe@ZnO samples. The antibacterial competency of the samples was also explored against Gram-positive (Bacillus subtilis, Staphylococcus aureus and Streptococcus salivarius) and Gram-negative (Escherichia coli) bacteria through the well diffusion method. The 50%g-C₃N₄/Fe@ZnO nanocomposite exhibited a superior antibacterial action compared to that of the rest of the samples. The exceptionally improved photocatalytic and antimicrobial efficiency of the 50%g-C₃N₄/Fe@ZnO composite was primarily accredited to the synergic outcome of the interface established between Fe@ZnO nanoparticles and g-C₃N₄ nanosheets.     

Controlled preparation of P-doped g-C3N4 nanosheets for efficient photocatalytic hydrogen production

Hydrogen production by photolysis of water by sunlight is an environmentally-friendly preparation technology for renewable energy. Graphitic carbon nitride (g-C₃N₄), despite with obvious catalytic effect, is still unsatisfactory for hydrogen production. In this work, phosphorus element is incorporated to tune g-C₃N₄'s property through calcinating the mixture of g-C₃N₄ and NaH₂PO_2, sacrificial agent and co-catalyst also been supplied to help efficient photocatalytic hydrogen production. Phosphorus (P) doped g-C₃N₄ samples (PCN-S) were prepared, and their catalytic properties were studied. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and ultraviolet diffuse reflection (UV-DRS) were used to study their structures and morphologies. The results show that the reaction rate of PCN-S is 318 μmol h⁻¹ g⁻¹, which is 2.98 times as high as pure carbon nitride nanosheets (CN) can do. Our study paves a new avenue, which is simple, environment-friendly and sustainable, to synthesize highly efficient P doping g-C₃N₄ nanosheets for solar energy conversion.     

Facile synthesis of carbon self-doped g-C3N4 for enhanced photocatalytic hydrogen evolution

Graphite carbon nitride (g-C₃N₄) is an appealing metal-free photocatalyst for hydrogen evolution, but the potential has been limited by its poor visible-light absorption and unsatisfactory separation of photo-induced carriers. Herein, a facile one-pot strategy to fabricate carbon self-doped g-C₃N₄ composite through the calcination of dicyanamide and trace amounts of dimethylformamide is presented. The as-obtained carbon self-doped catalyst is investigated by X-ray photoelectron spectroscopy (XPS), confirming the substitution of carbon atoms in original sites of bridging nitrogen. We demonstrate that the as-prepared materials display remarkably improved visible-light absorption and optimized electronic structure under the premise of principally maintaining the tri-s-triazine based crystal framework and surface properties. Furthermore, the carbon doped g-C₃N₄ composite simultaneously weakens the transportation barrier of charge carriers, suppresses charge recombination and raises the separated efficiency of photoinduced holes and electrons on account of the extension of pi conjugated system. As a result, carbon self-doped g-C₃N₄ exhibits 4.3 times greater photocurrent density and 5.2 times higher hydrogen evolution rate compared with its bulk counterpart under visible light irradiation.     

新型g-C3N4/CuS复合材料的制备及光催化研究

一步水热法合成CuS修饰的石墨相氮化碳(g-C3N4/CuS)复合光催化剂,通过FE-SEM、XRD、FTIR、UV-Vis-DRS等手段对其进行了表征,利用Cr(VI)溶液考察了g-C3N4/CuS在可见光下的光催化还原性能.实验结果表明,g-C3N4/CuS复合光催化剂的光催化活性明显优于单一的g-C3N4和CuS.可见光照射下,180 min内Cr(VI)的去除率可达70％以上.CuS的引入不仅扩宽了g-C3N4的可见光吸收范围,而且降低了g-C3N4光生电子和空穴的复合率,从而显著提高g-C3N4的光催化活性.该复合材料的催化活性受溶液的pH值影响较大,酸性条件下更有利于光催化反应的进行;共存低浓度腐殖酸对Cr(VI)的去除没有显著影响.g-C3N4/CuS具有良好的可见光催化活性,可用于废水中Cr(VI)的光催化还原去除.     

SiO2/g-C3N4复合粉体制备及其光催化性能

以St?ber法制备出的二氧化硅(SiO2)微球和三聚氰胺为原料,两者按一定质量比混合后得到前驱体,通过煅烧该前驱体可成功获得SiO2/g-C3 N4复合粉体.利用XRD、SEM、UV-Vis和BET等表征手段对获得的复合粉体进行物相组成、形貌、可见光吸收性能以及比表面积大小等进行分析和测试.结果表明,改进的St?be...     

Rational design of MoS2/g-C3N4/ZnIn2S4 hierarchical heterostructures with efficient charge transfer for significantly enhanced photocatalytic H2 production

The rational design of hierarchical heterojunction photocatalysts with efficient spatial charge separation remains an intense challenge in hydrogen generation from photocatalytic water splitting. Herein, a noble-metal-free MoS₂/g-C₃N₄/ZnIn₂S₄ ternary heterostructure with a hierarchical flower-like architecture was developed by in situ growth of 3D flower-like ZnIn₂S₄ nanospheres on 2D MoS₂ and 2D g-C₃N₄ nanosheets. Benefiting from the favorable 2D-2D-3D hierarchical heterojunction structure, the resultant MoS₂/g-C₃N₄/ZnIn₂S₄ nanocomposite loaded with 3 wt% g-C₃N₄ and 1.5 wt% MoS₂ displayed the optimal hydrogen evolution activity (6291 μmol g^?1 h^?1), which was a 6.96-fold and 2.54-fold enhancement compared to bare ZnIn₂S₄ and binary g-C₃N₄/ZnIn₂S₄, respectively. Structural characterizations reveal that the significantly boosted photoactivity is closely associated with the multichannel charge transfer among ZnIn₂S₄, MoS₂, and g-C₃N₄ components with suitable band-edge alignments in the composites, where the photogenerated electrons migrate from g-C₃N₄ to ZnIn₂S₄ and MoS₂ through the intimate heterojunction interfaces, thus enabling efficient electron-hole separation and high photoactivity for hydrogen evolution. In addition, the introduction of MoS₂ nanosheets highly benefits the improved light-harvesting capacity and the reduced H₂-evolution overpotential, further promoting the photocatalytic H₂-evolution performance. Moreover, the MoS₂/g-C₃N₄/ZnIn₂S₄ ternary heterostructure possesses prominent stability during the photoreaction process owing to the migration of photoinduced holes from ZnIn₂S₄ to g-C₃N₄, which is deemed to be central to practical applications in solar hydrogen production.     

Facile Synthesis of Zn Doped g-C3N4 for Enhanced Visible Light Driven Photocatalytic Hydrogen Production

Topics in Catalysis - The present work reports a facile strategy to develop L-arginine mediated Zn doped graphitic carbon nitride (g-C3N4) and its enhanced photocatalytic activity. The...     

Environmentally friendly supermolecule self-assembly preparation of S-doped hollow porous tubular g-C3N4 for boosted photocatalytic H2 production

Utilization of graphitic carbon nitride (g–C₃N₄)–based materials for photocatalytic hydrogen production to alleviate energy problems is a hot topic of research nowadays, thus the design and synthesis of highly efficient g-C₃N₄ materials remains a significant challenge. Herein, the sulphur-doped hollow porous tubular g-C₃N₄ (S-HPTCN) was successfully synthesized by a facile environmentally friendly supramolecule self-assembly strategy. Photocatalytic H₂ evolution tests show that the as-prepared optimal S-HPTCN achieved a high H₂ production of up to 22.04 mmol g⁻¹ h⁻¹ with the turnover frequency (TOF) of 429.7 h⁻¹ and the apparent quantum efficiency (AQE) of as high as 7.8% at wavelength of 420 nm. The enhancement of remarkable photocatalytic H₂ performance is mainly attributed to the synergetic effect of morphology and elemental doping. This research provides an effective design idea of developing high-efficient g–C₃N₄–based material for solar to hydrogen.