RETRACTED: The fabrication of self-floating Ti3+/N co-doped TiO2/diatomite granule catalyst with enhanced photocatalytic performance under visible light irradiation

Abstract

Abstract Powdery photocatalyst has long been investigated and developed, yet its disadvantages such as low light-harvesting and reuse capability in suspension system have greatly hindered its practical application. The proposal of floating photocatalyst provided an alternative method to overcome the above limitations. In this work, TiO2 nanoparticles were doped by Ti3+ and N, and dispersed onto natural porous mineral diatomite via sol-gel method. The obtained black powder was granulated to produce floating granule catalyst (black Ti3+/N co-doped TiO2/diatomite hybrid granule), denoted as b/N-TDHG. The synergy between Ti3+ and N dopants, as well as diatomite and TiO2 were studied. The photoactivity of b/N-TDHG was investigated via the degradation of antibiotic tetracycline (TC) solution under visible light irradiation, and then the optimal co-doping amount and granule dosage were determined. The optimal granule catalyst presented its removal rate of TC as 92.0% within 150 min, and its rate constant was 0.0144 min−1, while the corresponding powdery sample showed the removal rate of TC as 90.5% during the same period, with its rate constant as 0.0135 min−1. Moreover, floating b/N-TDHG could simply be filtrated from TC solution, and the removal rate slightly dropped to 89.6% after 5 repetitions, presenting good reusability.