Photoeletrocatalytic activity of an n-ZnO/p-Cu2O/n-TNA ternary heterojunction electrode for tetracycline degradation.
In this study, a novel ternary heterojunction n-ZnO/p-Cu2O/n-TiO2 nanotube arrays (n-ZnO/p-Cu2O/n-TNA) nanophotocatalyst with a sandwich-like nanostructure was constructed and applied for the photoelectrocatalytic (PEC) degradation of typical PPCPs, tetracycline (TC). The ternary heterojunction n-ZnO/p-Cu2O/n-TNA was obtained by depositing Cu2O on the surface of TNA via sonoelectrochemical deposition (SED) and subsequently building a layer of ZnO onto the p-Cu2O/n-TNA surface through hydrothermal synthesis. After being deposited by the Cu2O, the absorption-band edge of the p-Cu2O/n-TNA was obviously red-shifted to the visible region (to 505 nm), and the band gap was reduced from its original 3.20 eV to 2.46 eV. The band gap absorption edge of the ternary n-ZnO/p-Cu2O/n-TNA is similar to that of p-Cu2O/n-TN and extends the visible spectrum absorption to 510 nm, corresponding to an Eg value of about 2.43 eV. Under illumination of visible light, the photocurrent density of the ternary heterojunction n-ZnO/p-Cu2O/n-TNA electrode at 0.5 V (vs. Ag/AgCl) was more than 106 times as high as that of the pure TNAs electrode, 3.6 times as high as that of the binary heterojunction p-Cu2O/n-TNA electrode. The degradation of TC indicated that the ternary heterojunction n-ZnO/p-Cu2O/n-TNA electrode maintained a very high photoelectrocatalytic activity and excellent stability and reliability. Such kind of ternary heterojunction electrode material has a broad application prospect not only in pollution control but also in many other fields.
School of Environmental Science and Engineering, Shanghai Jiao Tong University, No. 800 Dongchuan Rd, Shanghai 200240, China.
Jinhua
J
Li
Shubin
S
Lv
Yanbiao
Y
Liu
Jing
J
Bai
Baoxue
B
Zhou
Xiaofang
X
Hu
D000900:Anti-Bacterial Agents / Q000737:chemistry*; D002384:Catalysis; D003300:Copper / Q000737:chemistry / Q000528:radiation effects; D004563:Electrochemistry; D004566:Electrodes; D043942:Nanotubes / Q000737:chemistry / Q000528:radiation effects; D055668:Photochemical Processes; D013752:Tetracycline / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry / Q000528:radiation effects; D014874:Water Pollutants, Chemical / Q000737:chemistry; D015034:Zinc Oxide / Q000737:chemistry / Q000528:radiation effects
D000900:Anti-Bacterial Agents; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D003300:Copper; D014025:Titanium; D013752:Tetracycline; D015034:Zinc Oxide; C000520:cuprous oxide
CB; Cu(2)O; PEC; Photoeletrocatalytic oxidation; SED; TC; TNA; Ternary heterojunction; TiO(2) nanotube arrays; VB; ZnO; conduction band; photoelectrocatalytic; sonoelectrochemical deposition method; tetracycline; valence band