Pure ZnO thick film, prepared by screen-printing technique, was almost insensitive to NH3. Pure ZnO thick films were surface modified with MnO2 by dipping them into 0.01 M aqueous solution of manganese chloride (MnCl2...Pure ZnO thick film, prepared by screen-printing technique, was almost insensitive to NH3. Pure ZnO thick films were surface modified with MnO2 by dipping them into 0.01 M aqueous solution of manganese chloride (MnCl2) for different intervals of time and fired at 500℃ for 12 h. The grains of MnO2 would disperse around the grains of ZnO base material. The MnO2 modified ZnO films dipped for 30 min were observed to be sensitive and highly selective to NH3 gas at room temperature. An exceptional sensitivity was found to low concentration (50 ppm) of NH3 gas at room temperature and no cross sensitivity was observed even to high concentrations of other hazardous and polluting gases. The effects of surface microstructure and MnO2 concentrations on the sensitivity, selectivity, response and recovery of the sensor in the presence of NH3and other gases were studied and discussed. The better performance could be attributed to an optimum number of surface misfits in terms of MnO2 on the ZnO films.展开更多
利用动电位线性慢扫描、交流阻抗、恒流放电、析气、扫描电子显微镜法(SEM)等方法,研究了含铝5.4×10-5的Zn-3×10-4Bi-3×10-4 In合金的物性及其电化学行为。结果表明:从表面到体相Al的分布逐渐降低,含铝使合金锌粉颗粒表...利用动电位线性慢扫描、交流阻抗、恒流放电、析气、扫描电子显微镜法(SEM)等方法,研究了含铝5.4×10-5的Zn-3×10-4Bi-3×10-4 In合金的物性及其电化学行为。结果表明:从表面到体相Al的分布逐渐降低,含铝使合金锌粉颗粒表面具有较低的粗糙度,提高了合金表面的均一性与锌阳极活性。与不含铝锌合金阳极相比,由含铝锌负极所组装的LR6型碱性锌锰电池室温150 m A恒流放电的容量提高了15.48%;碱锰电池的析气量从0.25 m L减少至0.04 m L。展开更多
Based on studies of controlling NOx from nitric acid exhaust gas domestic and abroad, this paper has developed a new technique on removal of NOx and production of aby-product with high added value-MnO2. Experimentshow...Based on studies of controlling NOx from nitric acid exhaust gas domestic and abroad, this paper has developed a new technique on removal of NOx and production of aby-product with high added value-MnO2. Experimentshows, pyrolusite, whose valid composition is MnO2 , of absorbing NOx has the following characteristics: quick, low cost, no secondary pollutant. Moreover, exhaust gas can attain the required standards. If the temperature of the pyrolusite serum is 30℃ , pH = 4, containing 90 g/L MnO2, the absorptivity for 3 000 mg/m3 NOx is 89. 2%. Furthermore, few of the impurities in pyrolusite dissolve in the absorption mother solution. The purification cost of product is very low. The purity of end product MnO2 is more than 99. 995% after purifying. Therefore, it is workable for the new technique on economy and technology. There are also obvious environmental benefits and marked economic returns.展开更多
文摘Pure ZnO thick film, prepared by screen-printing technique, was almost insensitive to NH3. Pure ZnO thick films were surface modified with MnO2 by dipping them into 0.01 M aqueous solution of manganese chloride (MnCl2) for different intervals of time and fired at 500℃ for 12 h. The grains of MnO2 would disperse around the grains of ZnO base material. The MnO2 modified ZnO films dipped for 30 min were observed to be sensitive and highly selective to NH3 gas at room temperature. An exceptional sensitivity was found to low concentration (50 ppm) of NH3 gas at room temperature and no cross sensitivity was observed even to high concentrations of other hazardous and polluting gases. The effects of surface microstructure and MnO2 concentrations on the sensitivity, selectivity, response and recovery of the sensor in the presence of NH3and other gases were studied and discussed. The better performance could be attributed to an optimum number of surface misfits in terms of MnO2 on the ZnO films.
文摘利用动电位线性慢扫描、交流阻抗、恒流放电、析气、扫描电子显微镜法(SEM)等方法,研究了含铝5.4×10-5的Zn-3×10-4Bi-3×10-4 In合金的物性及其电化学行为。结果表明:从表面到体相Al的分布逐渐降低,含铝使合金锌粉颗粒表面具有较低的粗糙度,提高了合金表面的均一性与锌阳极活性。与不含铝锌合金阳极相比,由含铝锌负极所组装的LR6型碱性锌锰电池室温150 m A恒流放电的容量提高了15.48%;碱锰电池的析气量从0.25 m L减少至0.04 m L。
基金Supported by the Key Research Program Fundation of the Education Bureau of Sichuan Province in China(1999127)
文摘Based on studies of controlling NOx from nitric acid exhaust gas domestic and abroad, this paper has developed a new technique on removal of NOx and production of aby-product with high added value-MnO2. Experimentshows, pyrolusite, whose valid composition is MnO2 , of absorbing NOx has the following characteristics: quick, low cost, no secondary pollutant. Moreover, exhaust gas can attain the required standards. If the temperature of the pyrolusite serum is 30℃ , pH = 4, containing 90 g/L MnO2, the absorptivity for 3 000 mg/m3 NOx is 89. 2%. Furthermore, few of the impurities in pyrolusite dissolve in the absorption mother solution. The purification cost of product is very low. The purity of end product MnO2 is more than 99. 995% after purifying. Therefore, it is workable for the new technique on economy and technology. There are also obvious environmental benefits and marked economic returns.
