摘要
针对具有工业化应用前景的大尺寸掺硼金刚石(BDD)电极难于用微波等离子体化学气相沉积(MPCVD)技术制备的问题,通过以热等静压(HIP)石墨片取代传统的硅基体,结合预涂覆金属过渡层及采用适于大面积生长的高功率碟形腔型MPCVD装置,沉积生长直径达100 mm的石墨基掺硼金刚石(BDD)涂层电极。BDD薄膜沉积前,使用热化学气相沉积(TCVD)工艺在石墨基体表面预镀覆金属铌作为过渡层,以避免金刚石沉积阶段石墨基体剧烈氢刻蚀,提高金刚石形核率并增强膜材致密完整性;MPCVD沉积BDD工艺条件为CH_(4)浓度3%、乙硼烷掺杂源浓度B/C为7500×10^(-6)、微波功率7.5 kW、沉积气压10.5 kPa、基体温度860℃、生长时间10 h。通过场发射扫描电子显微镜(FESEM)、拉曼光谱(Raman)、X射线衍射(XRD)等技术对所制备薄膜进行表征,SEM表征表明在直径100 mm石墨基片上生长的BDD厚度达13μm,晶粒尺寸约10μm,且为典型的柱状晶结构;拉曼光谱中仅存在金刚石和与硼掺杂相关的特征峰,而XRD图谱揭示所制备样品为纯净的金刚石相。同时不同区域的SEM和Raman检测结果显示BDD在整个直径100 mm的区域内覆盖完整,且有较好的均匀性和一致性。循环伏安扫描曲线结果显示该石墨基BDD具有较大电势窗口(2.8 V),保持较高的电化学反应活性和较好的稳定性。本文研究表明采用合适的基材和预处理技术,可通过MPCVD方法获得大尺寸高质量的BDD涂层电极。
At present,boron-doped diamond(BDD)electrode is considered as an optimal electrode material for its excellent performance,which is often used in electrochemical oxidation of organic contaminants due to its chemical properties.The large size BDD film electrodes used in industrial applications were mainly obtained by hot filament chemical vapor deposition(HFCVD)method,but HFCVD method was difficult to ensure the high quality of the prepared electrodes to meet the requirements of large-scale engineering applications.Graphite itself was a good electrode material,and CVD diamond electrode coated on graphite substrate was expected to be a better one.Moreover,graphite had superior size stability which helped improve thermal shock resistance and prevented substrate from breaking after the microwave plasma chemical vapor deposition(MPCVD)processes like silicon substrate.It was still difficult to prepare BDD film electrode with large size through MPCVD technology,which had potential industrial ability of increasing production capacity and application scale.In order to solve this problem,graphite substrate with a diameter of 100 mm prepared by hot isostatic pressure(HIP)method was used to replace conventional silicon substrate.In combination with a surface pretreatment using metal transition layers,BDD film was deposited on the graphite substrate using a high-power disc-type cavity MPCVD system for higher deposition rate and purer growth environment.Before BDD film deposition,metal niobium layer was pre-deposited on the graphite substrate using thermal chemical vapor deposition(TCVD),which could avoid the strong etching of hydrogen plasma for the graphite substrate and improve the nucleation rate of diamond as well as further enhance the compactness of as-obtained BDD film.The typical parameters for BDD film deposition were as the following:the rate of methane and hydrogen to be 3%,atomic ratio of boron and carbon to be7500×10^(-6),microwave power to be 7.5 kW,chamber pressure to be 10.5 kPa,substrate temperature to be abo
作者
陈卓
熊鹰
王兵
杨森
王国欣
Chen Zhuo;Xiong Ying;Wang Bing;Yang Sen;Wang Guoxin(School of Materials Science&Engineering,Southwest University of Science and Technology,Mianyang 621010,China;State Key Laboratory for Environmental-Friendly Energy Materials,Mianyang 621010,China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2021年第7期828-835,共8页
Chinese Journal of Rare Metals
基金
四川省重点研发项目(20186120413)
四川省科技计划重点研发项目(2019YFG0065)资助。
