锶掺杂MoS_(2)(101)晶面的增长及压电增强近红外光催化氨硼烷制氢  

Doping of strontium in MoS_(2) widened d-spacing of plane(101)and piezo-enhanced photocatalytic evolution of hydrogen from ammonia borane upon near-infrared irradiation

作　　者：周漪雯 黄匡正 刘文晓 孟则达 罗莉[1,2] 刘守清 ZHOU Yiwen;HUANG Kuangzheng;LIU Wenxiao;MENG Zeda;LUO Li;LIU Shouqing(School of Chemistry and Life Sciences,SUST,Suzhou 215009,China;Jiangsu Key Laboratory for Environment Functional Materials,Suzhou 215009,China)

机构地区：[1]苏州科技大学化学与生命科学学院,江苏苏州215009 [2]江苏省环境功能材料重点实验室,江苏苏州215009

出　　处：《苏州科技大学学报（自然科学版）》2021年第4期56-66,共11页Journal of Suzhou University of Science and Technology（Natural Science Edition）

基　　金：国家自然科学基金资助项目(21576175);江苏省产业前瞻项目(BE2015190);江苏省研究生科研与实践创新计划项目(SJCX19_0847)。

摘　　要：报道了锶掺杂二硫化钼(Sr-MoS_(2))改变(101)面间距,增强了压电近红外NH_(3)BH_(3)释放氢气。X射线衍射(XRD)显示,锶原子掺杂使得MoS_(2)晶体中(002)晶面的面间距从6.71A压缩到6.43A,但其衍射峰显著增强,表明锶掺杂促进了(002)晶面的晶化。与此同时,锶掺杂使得(101)晶面的面间距从2.66A增加到2.70A,显示锶垂直于(101)晶面生长,这是因为锶的原子半径2.15A大于钼的原子半径2.01A。透射电子显微镜(TEM)观测到规整的(002)晶面,其面间距6.43A与XRD衍射角计算值一致,显示锶掺杂进入了MoS_(2)晶格中。X射线光电子能谱(XPS)证实锶存在于MoS_(2)中。紫外-可见-近红外(UV-Vis-NIR)漫反射光谱显示Sr-MoS_(2)带隙为0.84 eV,而纯MoS_(2)带隙为0.94 eV,这种带隙的降低有利于吸收近红外光。在最佳条件下,Sr-MoS_(2)压电近红外光催化0.05 mol·L^(-1)NH_(3)BH_(3)水溶液,在12 h氢气产率是1.22 mmol·(g·h)^(-1),而纯MoS_(2)的氢气产率只有0.35 mmol·(g·h)^(-1)。由于压电效应是结构的不对称所致,因此,锶掺杂导致MoS_(2)(101)面间距增加,从而导致压电效应的增加,最终导致产氢率的提高。Piezo-electric effect is ascribed to the asymmetry of structure forced by mechanics.The paper reports the efficient release of hydrogen from ammonia borane containing 19.6 wt%of hydrogen mass based on the piezoelectric photocatalysis of strontium-doped MoS_(2)(Sr-MoS_(2))due to the widened d-spacing of plane(101)as the catalyst under near-infrared irradiation.XRD patterns display that the doping of strontium atoms shortened the d-spacing of the(002)planes from 6.71Ato 6.43A,but facilitated the crystallization of the(002)planes.It also shows that the strontium atoms in MoS_(2) grew and were perpendicular to the(101)planes during doping and widened the d-spacing of the(101)planes from 2.66Ato 2.70Abecause the atom radius of strontium(2.15A)is larger than that of molybdenum(2.01A).The more regularly arranged(002)planes were observed,and the d-spacing of 6.43Awas in agreement with the value calculated by XRD angle,which confirms the existence of strontium in MoS_(2) lattices.UV-Vis-NIR diffuse reflectance spectra indicated that the band gap of Sr-MoS_(2) is 0.84 eV,whereas the one of the as-synthesized MoS_(2) is 0.94 eV.Under optimal conditions,the hydrogen yield based on Sr-MoS_(2) catalyst from aqueous NH_(3)BH_(3) solution was 1.22 mmol·(g·h)^(-1),whereas that of pristine MoS_(2) was only 0.35 mmol·(g·h)^(-1) under ultrasonic and 850 nm near-infrared irradiation at 12 h.The boosted yield of hydrogen was assigned to the enhanced piezoelectric effect due to the doping of strontium in MoS_(2) resulting in the widened d-spacing of plane(101),because the piezo-current of Sr-MoS_(2) was much larger than that of pristine MoS_(2).

关 键 词：锶掺杂硫化钼 压电光催化 析氢 近红外辐射 氨硼烷 

分 类 号：O430.10[机械工程—光学工程]