0-D/3-D heterojunction composite constructed by decorating transition metal oxide nanoparticle on peony-like ZnO hierarchical microstructure for improved photodegradation of palm oil mill effluent

作者：Chin, Ying-Hui; Sin, Jin-Chung^*; Lam, Sze-Mun; Zeng, Honghu^*; Lin, Hua; Li, Haixiang; Mohamed, Abdul Rahman

来源：Optik, 2022, 260: 169098.

DOI：10.1016/j.ijleo.2022.169098

• CuO
• Nb2O5
• WO3
• Peony-like ZnO
• Heterojunction
• Photocatalytic degradation
• Industrial wastewater treatment

A series of transition metal oxide nanoparticles decorated on peony-like hierarchical porous ZnO (MO/ZnO, where MO = CuO, WO3 and Nb2O5) was synthesized using a precipitation-ultrasonic method. The X-ray diffraction, energy dispersive X-ray and fourier-transform infrared spectroscopy findings indicated the existence of both MO and ZnO in the composites. The field-emission scanning electron microscope and transmission electron microscope observations revealed that the MO nanoparticles were well dispersed onto peony-like ZnO hierarchical microstructure. Furthermore, the enhanced visible light absorption abilities of MO/ZnO were confirmed by UV-vis diffuse reflectance spectroscopy. The photocatalytic effectiveness of MO/ZnO was investigated by palm oil mill effluent (POME) degradation under UV irradiation. Among them, Nb2O5/ZnO composite exhibited the best photo degradation efficiency (91.7%) and the highest rate constant (0.0102 min(-1)) after 240 min irradiation. Moreover, a complete decolorization of POME was observed after 30 min irradiation using Nb2O5/ZnO composite. The phytotoxic effects of POME against the Vigna radiata seeds also reduced greatly after photocatalytically treated using Nb2O5/ZnO composite. Meantime, the product revealed great photocatalytic stability with the degradation efficiency retained more than 80% after 4 cycles. The radical trapping experiment demonstrated that hydroxyl radical and photogenerated hole played major role in POME degradation. The outstanding photoactivity of Nb2O5/ZnO composite can be explicated by efficient charge separation between Nb2O5 and ZnO where the evidence can be obtained from photoluminescence and terephthalic acid-photoluminescence probing analyses. The present study to construct these heterojunction composites can provide an innovative view to design highly effective photocatalytic system for the treatment of industrial wastewater.

• 单位
  桂林理工大学