包载型光催化剂可有效解决粉末催化剂处理水中污染物时的回收和再循环问题。以P25TiO₂为原料制备algCa/TiO₂凝珠，利用XRD、UV-Vis、FESEM、EDX等技术手段获得催化剂的结构、组成和光吸收性能，研究algCa/TiO₂吸附-光催化协同去除水中Cr（Ⅵ）的性能。结果表明，algCa裸珠对Cr（Ⅵ）的吸附去除率为14.5%；在30 W紫外汞灯照射下，algCa/TiO₂-9通过吸附-光催化将Cr（Ⅵ）还原为Cr（Ⅲ）的效率为66.9%。algCa/TiO₂表面基团与Cr（Ⅲ）产生的静电引力使催化剂表面残留Cr（Ⅲ），4次循环利用的algCa/TiO₂活性为53.8%。同时，提出了吸附-光催化反应机理。

A supported photocatalyst is preferred for practical water treatment applications of photocatalytic technology, which can solve the recovery and recycle problems of powder photocatalyst in photocatalytic degradation of pollutants in water. AlgCa/TiO₂ beads are prepared with P25TiO₂, sodium alginate and calcium chloride as raw materials. The composition, structure and light absorption properties of AlgCa/TiO₂ beads photocatalyst are characterized by means of XRD, UV-Vis DRS, TEM, FESEM and EDS, and the adsorption-photocatalytic performance to remove aqueous Cr(Ⅵ) are investigated. Experimental results show that adsorption removal rate of aqueous Cr(Ⅵ) by algCa bare beads is 14.5%. The reduction efficiency of Cr(Ⅵ) to Cr(Ⅲ) reaches 66.9% through synergy of adsorption and photocatalysis over algCa/TiO₂-9 beads under 30 W of ultraviolet light irradiation. The electrostatic attraction between surficial groups of algCa/TiO₂-9 beads and Cr(Ⅲ) causes residual Cr(Ⅲ) to leave on the surface of the beads. The activity of algCa/TiO₂ after four cycles of uses remains 53.8%. The adsorption-photocatalysis mechanism is revealed.