Preparation Of MoO₂ Nanocrystals And Its Application In SERS

With the rising interests on the research and development of high-conductivity metal oxides in the fields of energy and molecular detection,molybdenum dioxide?MoO₂?has attracted attention as a fully coordinated and metallic metal oxide material.Preliminary research shows that molybdenum dioxide has high chemical stability?insoluble in strong acids and bases?,good oxidation resistance and high conductivity,making MoO₂ as a potential candidate material in the field of energy storage electrodes,catalysts and surface enhanced Raman scattering.In particular,as a stable metal oxide with high free electron concentration,MoO₂ may form local surface plasmon resonance?LSPR?in the visible light band,thus becoming a potential cheap surface enhanced Raman spectroscopy?SERS?substrate material in replacement for noble metals such as Au and Ag.At present,research on MoO₂ is in the ascendant,and systematic researches in material preparation,morphology control,SERS measurement methods,SERS mechanism,and detection universality are required.Therefore,this thesis investigates the preparation of molybdenum dioxide and its SERS performance,the specific research contents and results are as follows:?1?The chemical vapor deposition method was used to independently control the evaporation and reaction of sulfur powder with molybdenum trioxide?MoO₃?powder through dual temperature zones.The effect of substrate,source material ratio and reaction time on the size and distribution of MoO₂ was revealed.Controllable preparation of dispersed MoO₂ nanosheets on different substrates is realized.?2?Based on the above MoO₂ nanosheets,taking Rhodamine?R6G?as an example,the SERS performance of MoO₂ nanosheets was explored.By studying the effects of laser power,collection time,and integration times in Raman measurement on the test results,we determined the standard procedure for SERS measurement of MoO₂ nanosheets.Based on the above procedure,we studied the SERS effect of MoO₂ nanosheets and found that MoO₂ nanosheets exhibited good SERS performance.The detection limit of R6G is better than 2×10^-8M,and the EFs can reach 1.41×10⁵.