Enhanced natural sunlight driven photocatalytic degradation under outdoor inconstant weather by Bi2WO6/WO3 heterojunctions

Weak sunlight irradiation intensity and inconstant weather conditions limit the practical application of photocatalysis in natural environment. In this work, efficient Bi2WO6 was synthesized using surfactant assistance strategy, which possesses superior photocatalytic activity under natural environment with outdoor sunlight as illumination source. Rod-like and sheet-like WO3 were synthesized by controlling rich and poor Cl- contents in precursor solutions, respectively, which were utilized to construct Bi2WO6/WO3 heterojunctions. Compared with pristine samples, Bi2WO6/WO3 exhibit enhanced tetracycline photodegradation performance under natural environment, whether on sunny day (sunlight intensity from 44.29 to 69.48 mW/cm2) or cloudy day (from 5.07 to 54.67 mW/cm2), even overcast day (from 2.83 to 18.99 mW/cm2), and the tetracycline degradation efficiencies reached 74.3% and 54.2% within 150 min on sunny and overcast days, respectively. Moreover, Bi2WO6/ WO3 exhibit the effective photodegradation performances toward methyl orange and rhodamine b, with elimination efficiencies of 63.7% and 99.0% within 50 min irradiation, respectively.