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Multiscale confinement nitridation in molybdenum carbide for efficient hydrogen production
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作者 Liming Dai chenchen Fang +10 位作者 Xiaoyuan Zhang Xuefeng Xu xuanxuan chen Xinyue Zong Xueming Hu Wenyao Zhang Liang Xue Pan Xiong Yongsheng Fu Jingwen Sun Junwu Zhu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第7期61-69,共9页
The molybdenum carbide(Mo_(2)C)has been regarded as one of the most cost-efficient and stable electrocatalyst for the hydrogen evolution reaction(HER)by the virtue of its Pt-like electronic structures.However,the inhe... The molybdenum carbide(Mo_(2)C)has been regarded as one of the most cost-efficient and stable electrocatalyst for the hydrogen evolution reaction(HER)by the virtue of its Pt-like electronic structures.However,the inherent limitation of high density of empty valence band significantly reduces its catalytic reactivity by reason of strong hydrogen desorption resistance.Herein,we propose a multiscale confinement synthesis method to design the nitrogen-rich Mo_(2)C for modulating the band structure via decomposing the pre-coordination bonded polymer in a pressure-tight tube sealing system.Pre-bonded c/N-Mo in the coordination precursor constructs a micro-confinement space,enabling the homogeneous nitrogenization in-situ happened during the formation of Mo_(2)C.Simultaneously,the evolved gases from the precursor decomposition in tube sealing system establish a macro-confinement environment,preventing the lattice N escape and further endowing a continuous nitridation.Combining the multiscale confinement effects,the nitrogen-rich Mo2C displays as high as 25%N-Mo concentration in carbide lattice,leading to a satisfactory band structure.Accordingly,the constructed nitrogen-rich Mo_(2)C reveals an adorable catalytic activity for HER in both alkaline and acid solution.It is anticipated that the multiscale confinement synthesis strategy presents guideline for the rational design of electrocatalysts and beyond. 展开更多
关键词 Molybdenum carbide Hydrogen evolution reaction Multiscale confinement synthesis Valence band modulation Nitrogen doping
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内消旋二苯甲酰酒石酸主导苝酰亚胺聚集体超分子手性的反Z-型相关
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作者 余月波 林晓妍 +2 位作者 陈萱萱 严小胜 江云宝 《中国科学:化学》 CAS CSCD 北大核心 2020年第12期1844-1852,共9页
CD-ee关系曲线常用以描述聚集体的超分子手性特征,其中线型和S(Z)-型相关已有诸多报道,但反S(Z)-型相关却鲜见报道.我们提出通过引入手性诱导剂的内消旋体,构建呈反Z-型相关的超分子聚集体.在手性二苯甲酰酒石酸对映体存在下,修饰以胍... CD-ee关系曲线常用以描述聚集体的超分子手性特征,其中线型和S(Z)-型相关已有诸多报道,但反S(Z)-型相关却鲜见报道.我们提出通过引入手性诱导剂的内消旋体,构建呈反Z-型相关的超分子聚集体.在手性二苯甲酰酒石酸对映体存在下,修饰以胍基的苝酰亚胺(PBI)分子因为胍基-羧酸根离子间的盐桥氢键作用,聚集形成超分子聚集体, CD信号与二苯甲酰酒石酸对映异构体的对映体过量值(ee)间呈Z-型相关,表现为手性放大特征;于对映体中引入内消旋二苯甲酰酒石酸,摩尔分数达到0.4或超过后观察到罕见的反Z-型相关."将军与士兵"法则实验亦呈现凹型相关曲线.吸收和CD光谱表明,对映异构体与内消旋体分别诱导的聚集体的结构和稳定性相近,后混合体系中聚集体之间无分子交换作用;但荧光光谱实验指示内消旋体更利于PBI染料分子的聚集,与对映体共存时主导聚集体的形成,导致超分子手性的反Z-型相关.研究结果为构筑反S(Z)-型相关的超分子聚集体提供了路径,有助于全面理解超分子手性. 展开更多
关键词 超分子手性 反S(Z)-型相关 CD-ee曲线 内消旋体 苝酰亚胺
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