Ordinary copper oxide is mainly used for the determination of carbon in gas analysis, and is also a catalyst commonly used in organic reactions and a raw material for preparing other copper compounds in an inorganic reaction. The particle size of nano-copper oxide is in the range of 1 to 100 nm. The particles of this size are in the transition region between macroscopic objects and microscopic particles, so they have volume effect, quantum size effect, surface effect and macroscopic quantum tunneling effect, so that light absorption , magnetic properties, thermal resistance, catalyst, chemical activity and melting point all exhibit special physicochemical properties different from ordinary copper oxide. As a new type of important functional material, it also has a good application prospect in biomedicine, sensors, catalytic materials and environmental management.
1. Desulfurization performance of nanometer copper oxide
With the prosperity of industrial production, a large amount of sulfides (such as hydrogen sulfide and sulfur dioxide) are discharged into the air, causing incalculable harm to the environment and humans. Studies have shown that some metal oxides have good desulfurization performance, and nano-copper oxide has the best desulfurization effect, and it is mainly used in desulfurization of flue gas. Yan Bo et al. proposed the concept of nano-desulfurizer and prepared nano-copper oxide desulfurizer by direct precipitation method. Experimental studies have found that nano-copper oxide can be used for desulfurization at room temperature, and the removal accuracy of H2S can reach below 0.05 mg/m3. Preferably, the product penetrates sulfur capacity by 25.3% at 3000 h−1 space velocity, which is higher than other desulfurizer products of the same type. In order to improve the utilization rate of nanometer copper oxide, the industry is mostly loaded on a carrier such as activated carbon, Cr2O3, ZrO2, ZnFeO4. Li et al. found that the desulfurization performance of CuO-Cr2O3 and CuO-CeO2 can meet the application of hot gas desulfurization, and its desulfurization activity and regeneration performance can be optimized by changing the fuel gas composition and temperature. Wang et al. prepared Cu/3 Y-ZrO2 nanomaterials by coprecipitation supercritical drying method and simulated flue gas. The desulfurization performance of the nanomaterials was studied by gas chromatography. The results show that the nanomaterials prepared by this method have good crystal form and sintered agglomeration. The phenomenon is not obvious, the desulfurization performance of the product is proportional to the content of copper supported, and inversely proportional to the specific surface area, and the desulfurization rate increases with the increase of temperature at 300-500 °C, and finally reaches a stable peak.
2. Catalytic performance of nanometer copper oxide
Copper is a transition metal element, has a special electronic structure different from other group metals, and has the property of gaining and losing electrons. It is widely used in the field of catalysts. As a biomass energy source, the increase of energy release efficiency in organic chemical reactions depends on the rapid and complete oxidative conversion of methanol. The catalytic activity of methanol oxidation reaction shows that the catalytic activity of nano-copper oxide is much higher than that of conventional catalysts. The methanol conversion rate can reach 90% at 210-220 °C; and the use of nano-copper oxide can catalyze the chemiluminescence of amino acids, which is commonly used in the field of biological science; Luo Mingfeng etc all found that the catalytic performance of nano-copper oxide is more pure than analytical CuO and Cu2+ were increased by 5.65 and 4.51 times, respectively. It was also found that nano-copper oxide can be used to improve the sensitivity of chemiluminescence detection of amino acids, which is of great significance for the detection of amino acids.
3. Antibacterial performance of nanometer copper oxide
Studies have shown that under the excitation of energy light greater than the forbidden band width, O2 and H2O in the environment can react with the generated hole-electron pair to generate free radicals such as active oxygen, which chemically react with organic substances in the cell. The cells are broken down to achieve the purpose of antibacterial. Pratibha Pandey et al. performed antimicrobial testing on nano-copper oxide. Mahapatra et al. [35] used liquid phase method to prepare copper oxide with a particle size of 80-160 nm. At the same time, the results showed that nano-copper oxide has good antibacterial ability against K. pneumoniae and Pseudomonas aeruginosa.
The special physicochemical properties of nano-copper oxide powder make it have more and more application potential, and with the advancement of technology, the preparation method and application research of nano-copper oxide are very active.