Abstract
A ultaviolet–visible light responded photocatalytic nanocomposite, silver/silver bromide/titanium dioxide, supported on graphene oxide (GO; silver/silver bromide/titanium dioxide/GO) was fabricated via a layer intercalation method using n-butylamine, cetyltrimethyl ammonium bromide, titanium dioxide and silver/silver bromide-intercalated GO successively. The resultant silver/silver bromide/titanium dioxide/GO exhibited much stronger visible light absorption and enhanced photocatalytic efficiency than titanium dioxide/GO and titanium dioxide. Furthermore, the degradation efficiency of silver/silver bromide/titanium dioxide/GO was improved when irradiated under light without the ultaviolet cut filter. The apparent degradation rate constants, k, for silver/silver bromide/titanium dioxide/GO, titanium dioxide/GO and titanium dioxide are 0.5192, 0.2273 and 0.0627 h−1. A possible photocatalytic degradation mechanism for degradation of 4-chlorophenol by silver/silver bromide/titanium dioxide/GO under irradiation with/without the ultaviolet cut filter was proposed. The factors including the visible light response from silver bromide, surface plasmon ‘hot’ electron effect from silver nanoparticles and efficient electron transfer among silver, silver bromide, titanium dioxide and GO are contributed to enhance the photocatalytic activity under visible light irradiation, while the additional factor of ultaviolet light response from titanium dioxide plays an important role under light irradiation without the ultaviolet cut filter. The resultant silver/silver bromide/titanium dioxide/GO possessed a good photochemical stability and reusability.
Highlights
Chlorophenol is an important organochloride intermediate that has been widely used as antiseptics, herbicides and pesticides.[1,2,3] most chlorophenols are moderate toxicity, they are easy to accumulate in the environment and human body, hard to degradate and have a strong medicinal taste and smell, leading serious risks to the environment and human health, and be classified as persistent organic pollutants (POPs)
The powder X-ray diffraction (XRD) peak of graphene oxide (GO) was observed at around 2θ 1⁄4 12 corresponding to the interlayer d-spacing of GO, which could be attributed to the intercalation of hydrophilic polar oxygen functional groups on the surface of graphite during its oxidation (Figure 2)
After GO intercalated with n-BA, the interlayer d-spacing enlarged to approximately 0.94 nm (2θ 1⁄4 9.4), which is slightly larger than the chain length of n-BA (0.73 nm)
Summary
Chlorophenol is an important organochloride intermediate that has been widely used as antiseptics, herbicides and pesticides.[1,2,3] most chlorophenols are moderate toxicity, they are easy to accumulate in the environment and human body, hard to degradate and have a strong medicinal taste and smell, leading serious risks to the environment and human health, and be classified as persistent organic pollutants (POPs). As a typical semiconductor photocatalyst, titanium dioxide (TiO2) has been widely studied for air and water purification applications, due to its unique properties such as high photocatalytic activity, low cost and non-toxicity.[4,5,6] the wide band gap (approximately 3.2 eV) of TiO2 limits its application to ultaviolet (UV) environments, which means it utilizes no more than 5% of the total solar energy. The resultant Ag/AgBr/TiO2/GO exhibited high UV-Vis light photocatalytic activity for the degradation of 4-chlorophenol (4-CP) solution and kept stable even after five consecutive photodegradation cycles. UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS) was carried out on an UV-3010 UV-Vis spectrophotometer (Hitachi, Japan)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
