Abstract The presence of toxic contaminants (like heavy metal ions and dyestuffs) in water causes an environmental threat and are challenging to discrete out from the water. Now a days, to overcome the challenge of the conventional process as well as for removal of these contaminants from water, mesoporous materials are used as an adsorbent or degradant. In this work, porous rock like bimetal-oxide monolith (Fe-Ni@SiO2) was synthesized via sol-gel method. Adsorption of heavy metal ions and photocatalytic degradation of Rhodamine B (RhB) dye by using Fe-Ni@SiO2 monolith was carried out. Adsorption experiments were performed in different batches by varying several parameters. The equilibrium between Fe-Ni@SiO2 and metal ion solution was achieved in approximately 70 min time at pH 6. The equilibrium data found to be well fitted using Freundlich and Langmuir adsorption isotherms. The maximum adsorption efficacy for Pb(II) and Cd(II) ions was 1018 mg/g and 974 mg/g, respectively. The adsorption process was found to be spontaneous and exothermic in nature. Also, for the RhB dye, the photocatalytic efficiency of the Fe-Ni@SiO2 monolith (using different amount) has been calculated under visible light source. We acquired the best results using 0.10 g/L Fe-Ni@SiO2 monolith and a further increase in the amount of photocatalyst result in an increase in opacity of the solution inside the reactor. The findings from this study suggests that the Fe-Ni@SiO2 monolith shows promising results for water treatment and could be employed as an alternative adsorbent/photocatalyst for toxic metal ion adsorption and dye degradation.

中文翻译：

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分层多孔Fe-Ni@SiO2整料对罗丹明-B的高效金属离子吸附和光降解

摘要 水中有毒污染物（如重金属离子和染料）的存在会导致环境威胁，并且很难从水中分离出来。现在，为了克服传统工艺的挑战以及从水中去除这些污染物，中孔材料被用作吸附剂或降解剂。在这项工作中，通过溶胶-凝胶法合成了多孔岩石，如双金属氧化物整料（Fe-Ni@SiO2）。使用Fe-Ni@SiO2整料进行重金属离子的吸附和罗丹明B（RhB）染料的光催化降解。通过改变几个参数在不同批次中进行吸附实验。Fe-Ni@SiO2 与金属离子溶液之间的平衡在 pH 6 下约 70 分钟内实现。发现平衡数据使用 Freundlich 和 Langmuir 吸附等温线拟合得很好。对 Pb(II) 和 Cd(II) 离子的最大吸附效率分别为 1018 mg/g 和 974 mg/g。发现吸附过程本质上是自发的和放热的。此外，对于 RhB 染料，在可见光源下计算了 Fe-Ni@SiO2 整料（使用不同量）的光催化效率。我们使用 0.10 g/L Fe-Ni@SiO2 整料获得了最佳结果，光催化剂用量的进一步增加导致反应器内溶液的不透明度增加。这项研究的结果表明，Fe-Ni@SiO2 整料在水处理方面显示出有希望的结果，可用作有毒金属离子吸附和染料降解的替代吸附剂/光催化剂。