In this study, salicylic acid-TiO₂@SiO₂@Ni/nZVI (SA-NFST) nanocomposites with rich hydroxyl groups were synthesized using in situ surface modified, co-precipitation, and sol-gel methods. A variety of techniques, including scanning electron microscopy (SEM), X-ray powder diffraction (XRD), vibrating sample magnetometer (VSM), transmission electron microscopy (TEM), the point of zero charge (PZC), UV–vis diffuse reflectance spectra (UV–vis), infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS), were used to characterize the properties of the nanoparticles.

The results showed that the SA-NFST exhibited high visible light-harvesting efficiency, easily magnetic separation, rich hydroxyl groups and hydroxyl radicals, and larger surface area. The adsorption and photo-oxidation of arsenite by the new materials were explored in different experimental conditions, including pH, initial arsenite concentration, catalyst dosage, contact time, and coexisting anions (PO₄³⁻, SiO₃²⁻, CO₃²⁻, and SO₄²⁻).

The maximum adsorption capacities (q_m) of As(III) onto SA-NFST calculated from Langmuir adsorption isotherm were 73.9 and 83.6 mg/g without and with visible light irradiation, respectively. >99.8% of As(III) (5.0 mg/L) was removed in the presence of 0.25 g/L SA-NFST nanoparticles (NPs) under 1.5 h visible light illumination. The residual concentration of As(III) (9.0 µg/L) was less than 10 µg/L, which is below the maximum allowable values in drinking water. As(III) removal may be due to the synergic combined effects of surface adsorption, photocatalytic oxidation under visible light illumination.

在这项研究中，使用原位表面改性，共沉淀和溶胶-凝胶法合成了具有丰富羟基的水杨酸-TiO ₂ @SiO ₂ @ Ni / nZVI（SA-NFST）纳米复合材料。多种技术，包括扫描电子显微镜（SEM），X射线粉末衍射（XRD），振动样品磁力计（VSM），透射电子显微镜（TEM），零电荷点（PZC），紫外可见漫反射光谱（UV-vis），红外光谱（FTIR）和X射线光电子能谱（XPS）用于表征纳米颗粒的特性。

结果表明，SA-NFST具有很高的可见光捕集效率，易磁分离，丰富的羟基和羟基自由基以及较大的表面积。在不同的实验条件下，包括pH，初始亚砷酸盐浓度，催化剂用量，接触时间和共存阴离子（PO ₄ ³⁻，SiO ₃ ²⁻，CO ₃ ^2−）探索了新材料对亚砷酸盐的吸附和光氧化作用。，以及SO ₄ ²⁻）。

根据Langmuir吸附等温线计算，As（III）在SA-NFST上的最大吸附容量（q _m）分别为73.9和83.6 mg / g（无和有可见光辐射）。在1.5 h可见光照射下，在0.25 g / L SA-NFST纳米颗粒（NPs）存在的情况下，去除了> 99.8％的As（III）（5.0 mg / L）。As（III）的残留浓度（9.0 µg / L）小于10 µg / L，低于饮用水中的最大允许值。As（III）的去除可能是由于在可见光照射下表面吸附，光催化氧化的协同作用所致。