Synthesis And Application Of Porous ZnO Nanorods

In order to solve the increasingly serious air pollution and energy shortage problem,people started monitoring emissions of harmful gases and seek to new type of clean energy.In terms of gas detection,gas sensor is widely used in the detection of poisonous and harmful gas with small volume,simple operation and low production cost.In the new energy,solar energy because of its abundant and easy to get,is considered to be one of the most promising new energy.Compared with common silicon solar cells,dye sensitized solar cell was attented with the advantages of simple and cheap.ZnO is a kind of important n-type semiconductor materials with a wide band gap of 3.37 eV.It has broad application in gas sensors,ultraviolet lasers and solar cells due to the great electronic transmission performance.In this paper,we first synthesized the slender nanorods structure of ZnC2O4 H2O precursor by hydrothermal method,The precursor was annealed to obtain porous ZnO nanorods with larger specific surface area and application in gas sensors and dye-sensitised cells,study the influence of zinc source and annealing temperature on the sensor and battery performance.Main work includes the following contents:First prepare ZnO " dandelion "nanomaterials by hydrothermal method,then use ZnO "dandelion" and commercial ZnO as zinc source,according to the method of transformation of oxalic acid salt to synthetic nanorod and block ZnC2O4 H2O precursor.And precursor of block 450 ?,the precursor of slender nanorods were annealed treatment with 430 ?,450 ?,470 ?,respectively.Their morphology and structure have been characterized by XRD,SEM,BET and TEM.After annealed,all products are based on porous structure,among them,the product of nanorod ZnC2O4.H2O precursor annealed with 450 ? has the most specific surface area.Annealed products and commercial ZnO as sensitive material of gas sensor respectively,and test their selectivity,the best working temperature,the sensitivity and stability.Under the best working temperature 300 ?,for 100 ppm ethanol,the sensitivity of ZnC2O4 H2O nanorod precursor annealed with 430 ?,450 ?,470 ? is 24,46,30,respectively,the sensitivity of ZnC2O4 H2O block precursor annealed with 450 ? is 13,far higher than the sensitivity of commercial ZnO.the product of nanorod ZnC2O4 H2O precursor annealed with 450 ? has excellent selectivity,sensitivity for 100 ppm of ethanol,acetone and ammonia is 46,14.8 and 3,respectively.Annealed products and commercial ZnO made as anode with the same thickness,assembled dye-sensitised cells and tested.the photoelectric conversion efficiency of ZnC2O4 H2O nanorod precursor annealed with 430 ?,450 ? and 470 ? is 2.07%,2.98%and 2.28%,respectively,the photoelectric conversion efficiency of ZnC2O4 H2O block precursor annealed with 450 ? is 1.62%,far higher than the photoelectric conversion efficiency of commercial ZnO.