Sorghum straw carbon assisted preparation of thin-sheet like BiOCl with boosted photocatalytic activity toward detoxification of three contaminants

Abstract

In this work, a one-pot hydrothermal method was employed to fabricate sorghum straw carbon (SSC) modified BiOCl catalysts. SSC not only operates as a template agent to regulate the microscopic morphology of BiOCl to form thinner lamellar structures but also constructs oxygen vacancies (OVs), which together enhance the photocatalytic ability. The samples were researched by Brunauer-Emmett-Teller (BET), X-ray diffractometer (XRD) and scanning electron microscope (SEM). Addition of SSC induce BiOCl to form a flower spherical-like structure assembled by thin sheets. Surface photovoltage spectroscopy (SPS) and electrochemical experiments confirm that the dense interlayer stacking provides more pathways for the separation of charges from bulk to the surface, and the thinner sheet thickness shortens the separation time for the charges, boosting the activity of the photocatalysts. The existence of the main reactive radicals (O2– and h+) in the photocatalytic system was investigated by trapping experiments. Photocatalytic activity of the samples was assessed by destruction of rhodamine B (RhB), tetracycline (TC) and perfluorooctanoic acid (PFOA). When the mass ratio of SSC/BiOCl is 0.75%, the catalyst shows the best photocatalytic activity. A reasonable photocatalytic enhancement mechanism was proposed in combination with the observation results.