In situ electrochemically etching-derived ZnO nanotube arrays for highly efficient and facilely recyclable photocatalyst

► A facile two-step electrochemical route was for the first time used to achieve ZnO nanotube arrays. ► The formation of ZnO nanotube arrays was based on the defect-induced etching mechanism. ► ZnO nanotube arrays exhibited enhanced photocatalytic efficiency due to high oxygen vacancies.