Study Of Preparation And Activity Of Nano-sulfide/K₂La₂Ti₃O₁₀ Composite Photocatalysts

Layered K2La2Ti3O10is a wide band gap semiconductor, which is only active underUV light irradiation. The smaller band gap semiconductor sensitized the wide band gapsemiconductor, which could shift the absorption edge to the visible light region. Nano-sulfide/K2La2Ti3O10composites were synthesized via combining two differentsemiconductors, which could enhance the photocatalytic activity under visible light.K2La2Ti3O10photocatalyst was synthesized via a stearic acid method. A series ofPbS/K2La2Ti3O10, CdS/K2La2Ti3O10and Cd1-xZnxS/K2La2Ti3O10composites were preparedvia a precipitation method. PbS, CdS and Cd1-xZnxS deposited on the K2La2Ti3O10surfaceexhibited a relatively good dispersity. ZnIn2S4/K2La2Ti3O10composite photocatalystswere synthesized via a hydrothermal route. The ZnIn2S4floriated microsphere whichcomprised of numerous nanosheets grew in the centre of many K2La2Ti3O10particles.The absorption edge of K2La2Ti3O10shifted to the visible light region upon introductionsof the PbS, CdS, Cd1-xZnxS and ZnIn2S4. The photocatalytic activities ofPbS/K2La2Ti3O10and CdS/K2La2Ti3O10were evaluated by photocatalytic degradation ofRhodamin B under visible light irradiation. The optimal dosage of PbS/K2La2Ti3O10andCdS/K2La2Ti3O10were0.35g and0.45g, respectively. After2h irradiation under visiblelight, the photocatalytic activities of degradation of10mg/L Rhodamin B for PbS(25wt.%)/K2La2Ti3O10and CdS(25wt.%)/K2La2Ti3O10composite photocatalyst were71.4%and97.8%, respectively. The photocatalytic activities of Cd1-xZnxS/K2La2Ti3O10andZnIn2S4/K2La2Ti3O10were measured by the amount of hydrogen production. The Cd1-xZnxS(30wt.%)/K2La2Ti3O10and ZnIn2S4(25wt.%)/K2La2Ti3O10exhibited the highestphotocatalytic activity. After3h visible light irradiation, the composites producted6.92mmol/g and6.29mmol/g H2, respectively.