Ultrathin porous Bi2WO6 with rich oxygen vacancies for promoted adsorption-photocatalytic tetracycline degradation

Exploring advanced photocatalysts for antibiotics degradation is highly desired but remains a challenge due to the lack of reasonable structural design and molecular oxygen activation. Herein, we deliberately design novel ultrathin porous Bi2WO6 with rich surface oxygen vacancies (VO-rich BWO) to enhance the tetracycline adsorption and photocatalytic reactive oxygen species generation. The oxygen vacancies in VO-rich BWO can narrow its bandgap to enhance the light absorption and introduce defect level, which can promote electron separation and transfer. Furthermore, the multiplication of oxygen vacancies increases the adsorption energy of O2, thus enhancing the chemisorption of O2, thereby activating O2 to produce more •O2−. Meanwhile, the porous structure enhances the adsorption capacity of VO-rich BWO to tetracycline molecules, allowing for a more efficient use of the •O2−. Taking advantage of the synergy, the rich oxygen vacancies Bi2WO6 nanosheets are able to degrade adsorbed tetracycline in situ with a degradation efficiency approximately 52.6 times that of bulk BWO, thus holding great potential for removing organic pollutants.