Preparation and photocatalytic activity of carbon black/black TiO2 composites

Black TiO2 (b-TiO2) was synthesized by hydrothermal and chemical reduction methods. Taking advantage of the adhesion effect of poly-dopamine (PDA), CB/b-TiO2 composite material was prepared by modifying b-TiO2 with carbon black (CB). The crystal structure, chemical composition and micro-morphology of the composites were characterized by XRD, XPS, SEM and TEM. The effect of mass ratio of CB to b-TiO2 on morphology and properties of CB/b-TiO2 was studied. The effect of the amount of CB/b-TiO2on photocatalysis degradation properties was also studied and the amount of CB/b-TiO2 was optimized. The results show that when the mass ratio of CB to b-TiO2 is 1:2, the obtained CB/ b-TiO2 has high light absorption performance in the wide spectrum range, CB/b-TiO2exhibits excellent photocatalytic performance. Besides, when the amount of CB/b-TiO2 is 0.5 g/L, the target pollutant malachite green solution MG (10 mg/L) can be degraded by 99.5% after 3 min. Besides, a high degradation rate of 89.2% can still be maintained after 5 cycles, showing good regeneration and utilization performance.