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MXene/MnO_(2)对有机微污染物的类芬顿氧化降解效能与机理
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作者 文涛 郭思胜 +6 位作者 赵恒新 郑宇琦 张馨月 顾鹏程 张塞 艾玥洁 王祥科 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第6期215-225,共11页
芬顿高级氧化技术是降解有机微污染物的有效手段.过一硫酸盐(PMS)类芬顿技术因具有高效的氧化剂利用率和较宽的pH操作范围,已成为目前工业中过氧化氢芬顿技术的一种有前途的替代品.非均相催化剂能够有效活化PMS,产生多种活性自由基,从... 芬顿高级氧化技术是降解有机微污染物的有效手段.过一硫酸盐(PMS)类芬顿技术因具有高效的氧化剂利用率和较宽的pH操作范围,已成为目前工业中过氧化氢芬顿技术的一种有前途的替代品.非均相催化剂能够有效活化PMS,产生多种活性自由基,从而氧化降解有机微污染物.二维过渡金属碳化物/氮化物(MXene)具有较好的电子传输效率和可调的表面官能团,是一种良好的非均相催化材料.然而,MXene的不稳定性、反应体系的自聚集作用和不明确的活性氧(ROS)生成机制极大地限制了它们在实际环境中的广泛应用.鉴于剥离的MXene中钛的高反应活性缺陷可以原位锚定过渡金属材料,本文通过氧化还原策略,将MnO_(2)纳米颗粒原位沉积在MXene纳米片上制备了MXene/MnO_(2)复合材料.X射线衍射图中(002)峰的偏移、透射电镜和电子衍射环图中交错的晶格条纹等表征结果表明,MnO_(2)纳米颗粒均匀地负载在剥离的MXene纳米片上.X射线光电子能谱证实了MXene表面钛缺陷与MnO_(2)纳米颗粒通过氧化还原作用相连接.同时,通过调整反应时间确定了18 h原位沉积制备的MXene/MnO_(2)具有最佳的产率和双酚A降解速率.此时的复合材料能够在4 min内活化PMS去除95.9%的BPA(50 mg/L),矿化效率达到了51.2%,表现出较好的催化性能.电子顺磁共振和淬灭实验结果表明,MXene/MnO_(2)活化PMS降解BPA为非自由基途径.实验观察结合密度泛函理论计算表明,大量暴露的锰位点有效吸附并活化PMS,从而促进了单线态氧的产生.通过高价Mn-oxo相直接生成1O_(2)的普遍途径具有较高的能垒(3.34 eV).相比之下,•OOH作为中间体产生1O_(2)的途径(1.84 eV)在能量上更可行.得益于MXene的快速电荷转移能力和MnO_(2)强PMS活化能力的双重优势,工程化的MXene/MnO_(2)/PVDF催化膜对京密引水渠河水中的有机微污染物表现出高效的活性和出色的长期稳定性.综上,本文通过氧化还原原位生长策略制得了MXene/MnO_(2)催化剂,并深入研究了其在类芬顿反应中催化降解有机微污染物的性能.通过实验表征和理论计算相结合的方法,揭示了该催化剂对有机微污染物的降解机理.本研究不仅为MXene基催化剂的设计和合成提供了新的思路,也为开发可广泛应用于实际水体中处理有机微污染物的催化剂提供了参考. 展开更多
关键词 MXene 二氧化锰 过一硫酸盐 单线态氧 类芬顿反应
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High performance organic transistors and phototransistors based on diketopyrrolopyrrole-quaterthiophene copolymer thin films fabricated via low-concentration solution processing 被引量:4
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作者 pengcheng gu Mengxiao Hu +7 位作者 Shang Ding guangyao Zhao Yifan Yao Feng Liu Xiaotao Zhang Huanli Dong Xiangke Wang Wenping Hu 《Chinese Chemical Letters》 SCIE CAS CSCD 2018年第11期1675-1680,共6页
Conjugated polymers have received considerable attentions over the past years due to their large-area potential applications via low-cost solution processing. Improving crystallinity of conjugated polymer molecules in... Conjugated polymers have received considerable attentions over the past years due to their large-area potential applications via low-cost solution processing. Improving crystallinity of conjugated polymer molecules in solution-processed thin films is crucial for their efficient charge transport and thus high performance optoelectronic devices. Herein, with diketopyrrolopyrrole-quaterthiophene (PDQT) copo/ymer as an example, it is found that by simply reducing the solution concentration for spincoating meanwhile with the assistance of post-annealing, significantly enhanced film crystallinity with formation of typical single crystalline domains is obtained, which benefits from the enough space for better molecular assembly especially at the semiconductor/dielectric interface. High performance polymer transistors and phototransistors were finally constructed based on the optimal lowconcentration (2 mg/mL) spin-coated PDQT films (~12 nm), which giving a high charge carrier mobility of 2.28 cm2 V-1 s-1 and a photoresponse on/off ratio of 2.1 ×107 at VG = 0 V under white light irradiation of 6mW/cm2. The results suggest that the bright future of PDQT crystalline films for large-area flexible integrated optoelectronic devices and the application of effective low-concentration processing approach in solution-processed organic electronics with reduced material waste. 展开更多
关键词 Conjugated polymer Thin film Low-concentration processing CRYSTALLINITY Molecular orders MOBILITY Optoelectronic property
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酸化氧化生物炭在含铀放射性废水处理中的应用研究 被引量:5
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作者 宋爽 顾鹏程 +3 位作者 陈中山 王祥学 张瑞 文涛 《中国科学:化学》 CAS CSCD 北大核心 2019年第1期155-164,共10页
随着核工业的发展,大量放射性污染物被排放到环境中,严重威胁着人类健康.生物炭材料作为一种可再生资源,具有丰富的孔隙结构和独特的表面化学性质,因此被广泛地应用于环境中污染物的去除.本文分别用煅烧处理后的咖啡渣(CG)和硝酸氧化后... 随着核工业的发展,大量放射性污染物被排放到环境中,严重威胁着人类健康.生物炭材料作为一种可再生资源,具有丰富的孔隙结构和独特的表面化学性质,因此被广泛地应用于环境中污染物的去除.本文分别用煅烧处理后的咖啡渣(CG)和硝酸氧化后的咖啡渣(CG-AO)作为生物炭吸附剂,研究了它们在模拟含铀废水中对U(Ⅵ)的去除性能,探究了溶液pH、反应时间、U(Ⅵ)的初始浓度、反应温度等因素对溶液中U(Ⅵ)去除率的影响,并通过X射线光电子能谱(XPS)光谱分析了相应的吸附机理.结果表明, pH对U(Ⅵ)在CG和CG-AO上的吸附效果影响显著,在近中性p H范围内表现出最佳的吸附效果;吸附反应能很快达到平衡,准二级动力学方程能够很好地拟合吸附动力学过程; Langmuir模型能较好地描述CG-AO对U(Ⅵ)的等温吸附过程,吸附容量与温度呈正相关;室温下改性得到生物炭材料对U(Ⅵ)的饱和吸附量约为251.71 mg g^(-1),几乎是未改性前生物炭的3倍(80.93 mg g^(-1)).基于XPS光谱分析发现, CG-AO对U(Ⅵ)的吸附机理可能是通过羧基与U(Ⅵ)形成表面配合物(O=C–O)_2UO_2,而CG则可能是通过羧基与水的协同作用与U(Ⅵ)形成表面配合物O=C–OUO_2(OH). 展开更多
关键词 U(VI) 生物炭 光谱分析 吸附机理
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One-pot synthesis of arginine modified hydroxyapatite carbon microsphere composites for efficient removal of U(Ⅵ) from aqueous solutions 被引量:3
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作者 Dongxu Yang Xiangxue Wang +6 位作者 Gang Song guixia Zhao Zhe Chen Shujun Yu pengcheng gu Hongqing Wang Xiangke Wang 《Science Bulletin》 SCIE EI CAS CSCD 2017年第23期1609-1618,共10页
Uranium was not only the main source of nuclear energy but also one of the long-lived radionuclide.Herein, a novel arginine modified hydroxyapatite carbon microsphere composites(defined as C@HAp/Arg) obtained promptly... Uranium was not only the main source of nuclear energy but also one of the long-lived radionuclide.Herein, a novel arginine modified hydroxyapatite carbon microsphere composites(defined as C@HAp/Arg) obtained promptly via a one-step mild hydrothermal method, was applied to remove U(Ⅵ) from aqueous solutions. Based on the characterization of transmission electron microscopy(TEM), scanning electron microscopy(SEM), Fourier transformed infrared spectroscopy(FT-IR), X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS), the synthesized C@HAp/Arg presented globular morphology and abundant functional groups(e.g., —COO^-), which were beneficial to its combination with U(Ⅵ). The interaction mechanism and removal capability of U(Ⅵ) on C@HAp/Arg were studied by batch adsorption technique and spectroscopy analysis. The results implied that U(Ⅵ) can form strong surface complexes on C@HAp/Arg. The kinetics adsorption of U(Ⅵ) followed pseudo-second-order kinetic model with high removal efficiency($95% within 5h at pH 5.0). The adsorption isotherms were well fitted by Langmuir model, implying that U(Ⅵ) uptake on C@HAp/Arg was monolayer coverage. It was found that the maximum adsorption capacities of CSs, C@HAp and C@HAp/Arg toward U(Ⅵ) were calculated to be 23.16,72.09 and 569.66 mg/g, respectively, at 298.15 K and pH 5.0, and thermodynamic parameters revealed that the adsorption processes of U(Ⅵ) were spontaneous and endothermic. In addition, effect of co-existed ions and CO_3^(2-)concentrations demonstrated that U(Ⅵ) adsorption on C@HAp/Arg was weakly interfered by foreign ions and carbonate concentrations. More importantly, the adsorption performance of U(Ⅵ) on C@HAp/Arg was still over $87% after five cycles. Therefore, it was noted that the versatile C@HAp/Arg could be potentially used as a powerful building block for the enrichment and disposal of U(Ⅵ) from aqueous solutions, which could efficiently reduce the potential toxicity of U(Ⅵ) in the U(Ⅵ)-contaminated water. 展开更多
关键词 U(Ⅵ) C@HAp/Arg composites Interaction mechanism Adsorption
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