Design and application of Au decorated ZnO/TiO2as a stable photocatalyst for wide spectral coverage.
A ternary nanostructured photocatalyst consisting of ZnO/TiO2/Au was designed to achieve an enhanced solar absorption due to the coupling of surface enhanced plasmonic absorption of metal and semiconductor excitons. TiO2coated ZnO rods with an aspect ratio of 8-12 were decorated with citrate capped gold nanoparticles for photocatalytic degradation of organic pollutants in simulated waste water under solar irradiation. Simulated waste water was prepared so as to get a mixture exhibiting a wide range of spectral distribution in the UV-visible region by deliberately mixing congo red, methylene blue and malachite green. Photo-oxidation of few phenolic compounds such as phenol, 4-chlorophenol and polycyclic aromatic hydrocarbons viz. anthracene and phenanthrene were also investigated in order to rule out the visible light sensitization of the dye molecules and confirm the photocatalytic efficacy of the ternary composite for a wide range of water pollutants under simulated solar irradiation. The composite exhibited enhanced photocatalytic activity and photoelectrochemical stability upon UV and visible light exposure. This enhanced efficiency was also corroborated with the photocarrier lifetime and chronoamperometric studies. Under simulated solar irradiation, UV light induced well separated charge carriers coupled with the visible light induced local surface plasmon resonance of AuNPs to exert significantly enhanced photocatalytic activity in a broad spectral region. This type of material may evolve as a novel photocatalyst for the efficient removal of organic contaminants in waste water and photoelectrochemical water splitting under the solar spectrum.
Sensor and Actuator Division, CSIR-Central Glass and Ceramic Research Institute, 196, Raja S.C. Mullick Road, Jadavpur, Kolkata 700032, India.
Soumita
S
Mukhopadhyay
Sensor and Actuator Division, CSIR-Central Glass and Ceramic Research Institute, 196, Raja S.C. Mullick Road, Jadavpur, Kolkata 700032, India.
Debabrata
D
Maiti
Chemistry Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Jadavpur, Kolkata 700032, India.
Sabyasachi
S
Chatterjee
Sensor and Actuator Division, CSIR-Central Glass and Ceramic Research Institute, 196, Raja S.C. Mullick Road, Jadavpur, Kolkata 700032, India.
Parukuttyamma Sujatha
PS
Devi
Chemistry Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Jadavpur, Kolkata 700032, India.
Gopinatha
G
Suresh Kumar