纳米B2O3/TiO2复合材料的制备及其对痕量银的分离富集性能研究与应用

制备了新型纳米B2O3/TiO2吸附材料,并采用扫描电镜(SEM)及红外光谱(IR)对其进行表征,优化了纳米B2O3/TiO2复合材料对试液中痕量银的吸附和解吸条件,建立了纳米B2O3/TiO2分离富集-原子吸收光谱测定痕量银的新方法。当pH 4.3时,在22℃下振荡20 min,Ag+能被该材料快速吸附,其静态饱和吸附容量为11.72 mg/g,吸附在纳米B2O3/TiO2上的Ag+可用0.1 mol/L HNO3-0.05 mol/L硫脲(1∶4)完全洗脱。该方法的检出限为2.01μg/L,线性范围为0.01～4.00 mg/L,相对标准偏差(RSD)为1.8%,加标回收率为95%～105%。方法应用于实际矿渣样品中痕量银的测定,结果满意。

Synthesis of Nano B2O3/TiO2 Composite and Its Application in Separation and Preconcentration of Trace Silver

Nano B2O3/TiO2 composite as a new sorbent was synthesized,and the characteristic of the synthesized material was studied by scanning electron microscope(SEM) and infrared spectrometry(IR).By investigating the optimal conditions of adsorption and desorption of nano B2O3/TiO2 composite for Ag+,a new method for the determination of trace silver was proposed.After oscillated for 20 minutes at 22 ℃ and pH 4.3,silver could be quantitatively adsorbed by nano B2O3/TiO2 composite,and the adsorption capacity was obtained to be 11.72 mg/g.The adsorbed silver could be eluted from the surface of the absorbent with 0.1 mol/L HNO3-0.05 mol/L thiourea(1 ∶ 4).Under the optimum experimental conditions,the calibration curve was linear over Ag+ concentration in the range of 0.01-4.00 mg/L,with a detection limit(3σ) of 2.01 μg/L.The RSD(n=11) for determination of 0.4 mg/L Ag+ was 1.8%.The spiked recoveries ranged from 95% to 105%.The method was applied in the determination of trace silver in slag samples with satisfactory results.