超细氧化亚铜的制备及在污水处理中的光催化应用

在碱性条件下,葡萄糖和水合肼还原硫酸铜制备了超细氧化亚铜。采用扫描电镜（SEM）和X衍射仪（XRD）进行表征,并在太阳光照条件下用氧化亚铜处理台盼蓝溶液,考察其对污水处理的光催化降解性能。考察了温度、台盼蓝初始浓度、光照时间、催化剂用量对台盼蓝溶液脱色率的影响,结果表明,超细氧化亚铜粒子粒径约为1μm,分散性较好;0.2g氧化亚铜在30℃太阳光照射1.5h条件下,处理50mL（15mg.L-1）的台盼蓝溶液脱色率为98.8%,氧化亚铜在重复使用4次后脱色率为87.8%。     

Mechanism of aventurine formation in copper-containing alkali-lead silicate glass

The mechanism of aventurine formation in copper-containing sodium-lead silicate glass is investigated. The methods of electron and optical microscopy are used to establish the role of iron monoxide in the stages of formation of a colloidal suspension of microdrops of metallic copper in the glass and the transformation of the latter into aventurine crystals.     

Electrochemical preparation of cuprous oxid powder: Part II. Process conditions

Practical electrosynthesis of cuprous oxide powder was carried out on a laboratory scale in a cell specially constructed both with and without a diaphragm under the various operating conditions guided by the authors' previous research. The electrolysis was appraised in terms of the quality of the cuprous oxide product, the electrodissolution of the copper anode, and the SEM microstructure of the cuprous oxide powder. In a cell having a diaphragm, of which nylon fabric is the best, the optimal electrolysis operating conditions are: 250gl^–1 NaCl, 0.1–1.0gl^–1 NaOH, 500–1500Am^–2, 80°C, perforated titanium sheet as the cathode, and around 3% cell volume of electrolyte circulation per minute. Under these conditions a product containing more than 97% cuprous oxide can easily be produced with very stable electrolysis and quite uniform dissolution of the copper anode. To eliminate the use of a diaphragm in the cell, the addition of sodium chromate, sodium dichromate, or calcium gluconate is effective in a sense, depending upon the requirements of the cuprous oxide product. For a product in which more than 95% cuprous oxide and no copper powder are required but a slightly higher content of chloride is allowable, sodium chromate and dichromate can be proposed for use with the former around 0.03–0.05gl^–1 and the latter around 0.020–0.025gl^–1, although the copper anode will not be perfectly evenly dissolved. For a product in which more than 97% cuprous oxide is demanded and a very small amount of copper powder is tolerated, calcium gluconate would be acceptable at around 4.5gl^–1 with quite even dissolution of the copper anode. As to the auxiliary additives, hydrazine hydrate has a negative effect on the quality of the cuprous oxide product. Sucrose can cause a small increase in the chloride content but can make the particles of cuprous oxide more compact thereby increasing sharply its apparent density. Hydroxylamine hydrochloride is the best auxiliary additive which has a positive effect on the purity of the cuprous oxide product but produces no obvious change in the microstructure on the cuprous oxide particles. Even though most work has been concentrated on the electrolytic process, the subsequent processes are equally important: 65–70°C, distilled water for washing, benzotriazole in ethanol solution for stabilization of the cuprous oxide, and 100°C at a vacuum of less than 20mm Hg for drying seem to be satisfactory. A vacuum drying temperature of 55–60°C may be more appropriate to ensure against any oxidation of the product.     

LaMer diagram approach to study the nucleation and growth of Cu2O nanoparticles using supersaturation theory

Uptake to cuprous oxide (Cu₂O) nanoparticle synthesis with various particle sizes and shapes via supersaturation chemistry approach (LaMer model) has been conducted. Ascorbic acid and maltodextrine as reducing agents and polyvinylpyrrolidone (PVP) as a surfactant were utilized for synthesis of Cu₂O nanoparticles in aqueous solution. The narrow particle size range was achieved by controlling the kinetics of nucleation and growth of particles to satisfy LaMer theory. This mean was performed utilizing different reducing agents (ascorbic acid and maltodextrin) and also, changing the reducing agent addition condition. The results showed the reducing agent addition condition, varying the size of Cu₂O nanoparticles from 89 nm to 74 nm for drop-wisely and at-once routes, respectively. The samples were characterized by XRD, SEM, and UV-Vis spectroscopy. The results indicate the shape of as-prepared cuprous oxide nanoparticles have close relationship with thermodynamic and kinetic conditions, and also reducing addition condition.     

Enamel with the aventurine effect

The aventurine effect is detected in chromium- and alkali-containing aluminoboron silicate glass and enamel based on it. The effect of the glass acidity and the ratio of the alkali oxides on the aventurine effect and the size of the crystals in glass and enamel is investigated. Translated from Steklo i Keramika, No. 4, pp. 30 – 31, April, 2000.     

STUDY OF PHOTOLUMINESCENCE IN GLASS*

The influence of composition and temperature on the fluorescence of glasses containing uranium and glasses containing cuprous oxide and stannous oxide was investigated. Secondary cations reduce the fluorescence of uranium in the glasses studied, depending to a certain extent on the electrostatic conditions they produce in the glass structure. The intensity of fluorescence as well as the structure of the spectrum diminishes in the order of phosphate, silicate, and borate glasses of equivalent compositions, which shows that fluorescence is favored by increase of oxygen in the glass structure without increasing the interfering secondary cations. Raising the temperature greatly diminishes the intensity of the fluorescence as well as the structure of the spectrum of glasses containing uranium. The fluorescence of the glasses containing cuprous oxide and stannous oxide as activators seems to be favored by increase in lime and increase in silica. These glasses possess appreciable phosphorescence, which appears to be enhanced by increase in silica and decrease in lime. A peculiar property of this type of luminescent glass is a maximum which it exhibits in its fluorescence-temperature relation-ship. There are indications that electrons are set free from the excited centers (copper atoms or small groups of copper atoms), which wander about in the glass structure.     

氧化亚铜微纳米结构的制备及光催化性能研究

以氨基酸为还原剂及配位剂,在碱性溶液中通过水热还原二价铜离子,制备了不同形貌的氧化亚铜微晶。考察了氨基酸对氧化亚铜微晶结构、尺寸、形貌的影响,提出了氧化亚铜微晶在水热条件下的可能形成机理,结果表明氨基酸是良好的形貌调节剂。以亚甲基蓝为探针分子,对所制备的氧化亚铜微晶的光催化性能进行了研究,发现其催化性能与形貌间存在着密切联系。     

Partially Reduced Cuprous Oxide Nanoparticles Formed in Porous Glass Reaction Fields

This paper describes the formation of cuprous oxide (Cu₂O) particles ∼10 nm in diameter and their reduction by hydrogen gas in porous glasses. Nanoparticles of Cu₂O coated with metallic copper are expected to show high third-order optical nonlinear susceptibilities (χ⁽³⁾). The porous glass is a medium in which nanoparticles can be partially reduced without forming agglomerations. Images obtained using transmission electron microscopy showed that particles with the desired core-shell structure were actually formed, even though some particles were not reduced uniformly from the surface. The χ⁽³⁾/α (α: absorbance) values in relevant conditions (10⁻¹³ esu·cm) were similar to that of copper because of the formation of a byproduct of copper nanoparticles on reduction.     

An integrated chemicalelectrochemical method for the recovery of copper from dilute solutions

The addition of reducing agents such as hydrazine or sodium sulphite to buffered dilute copper solutions containing chloride ions reduces cupric ions to cuprous ions chemically, thus by-passing this rate-determining electrochemical step. The subsequent electro-deposition of cuprous ions can then proceed readily and the overall faradaic efficiency, based on a 2 electron process, may reach 141%.     

溶剂热法可控合成纳米氯化亚铜

以氯化铜为铜源,甲醇、乙醇、异丙醇等为溶剂和还原剂,采用溶剂热法制备纳米氯化亚铜,探讨了温度、时间、还原剂等条件对所得氯化亚铜的形貌、粒径大小、物相组成的影响。结果表明,以乙醇、异丙醇为溶剂,在120~180℃反应24~48 h,Cu Cl纳米颗粒可在2~50 nm范围内有效调控。