Low-temperature and highly sensitive C_2H_2 sensor based on Au decorated ZnO/In_2O_3 belt-tooth shape nano-heterostructures

摘要

Gas sensors play a vital role on many aspects in our society, and have gained much progress, propelled by the development of nanoscience and nanotechnology. In this regard, metal oxides with heterojunc-tions have attracted tremendous attention owing to their enhanced gas sensing properties. Herein, belt-tooth shape Zn0/ln_2O_3 nano-heterostructures has been achieved through a chemical vapor depo sition process. The gas sensor fabricated from the as-prepared nano-heterostructures exhibits superior sensing performances for C_2H_2 gas at low operating temperature (90℃). Moreover, the Au decorated ZnO/ln_2O_3 nano-heterostructures (Au-ZnO/ln_2O_3) exhibit enhanced C_2H_2 sensing properties such as higher response, less response time, better selectivity and smaller deviation from the ideal value of power exponent. More significantly, the response to C_2H_2 gas is maintained well in 30 days, indicating good long-term stability. In addition, both the potential-barrier-controlled carrier transport model com bining with the surface depletion model and the unique properties of Au are presented to describe the C_2H_2 gas sensing mechanism of Au-ZnO/In_2O_3. This study offers an innovative methodology to design novel gas sensing materials and enhance gas sensing performances.