Biotemplating Synthesis of Graphitic Carbon-Coated TiO₂ and Its Application as Efficient Visible-Light-Driven Photocatalyst for Cr⁶⁺ Remove

Abstract

TiO2 and graphitic carbon (GC) composites with hierarchical pore structures were synthesized using Staphylococcus aureus (ATCC6538) as the biotemplate to modify Degussa P25 TiO2 powder. Then, the composites were applied as photocatalysts for Cr6+ reduction under visible light irradiation. X-ray diffraction, Raman spectroscopy, transmission electron microscopy, nitrogen adsorption–desorption analysis, and X-ray photoelectron spectroscopy demonstrated the presence of a GC coating layer and a unique anatase/rutile mixed crystal phase of TiO2 even after heating at 800 °C. The novel TiO2@GC composites, especially the S-P25-800 sample, which possessed abundant hierarchical mesoporous structures, exhibited strong catalytic activities in Cr6+ photoreduction under visible light. This work provides light to overcome the challenge on synthesis of GC modified TiO2 photocatalysts with the highly reactive but heat-labile anatase main crystal phase at high temperature. Furthermore, the present results demonstrated that TiO2@GC heterojunctions has a great potential to be used as efficient and economical photocatalysts for environmental contaminants remove.

Bi2S3–In2S3 Heterostructures for Efficient Photoreduction of Highly Toxic Cr6+ Enabled by Facet‐Coupling and Z‐Scheme Structure

“…[ 5–7 ] Photocatalytic Cr 6+ reduction has emerged as an attractive direction due to its potential to be environmental friendly, cheap, and sustainable. [ 1,8 ] Various photocatalysts have been reported for Cr 6+ reduction, including phlo‐@POF, [ 9 ] Cu 2 O/TiO 2 , [ 10 ] Zn(Ce, Mn)‐MOFs, [ 11 ] ZnWO 4 , [ 5 ] SnS 2 –In 2 S 3 , [ 12 ] and Gd(OH) 3 . [ 6 ] However, many of the reported materials show limited photocatalytic efficiency due to their wide bandgaps limiting their light absorption ability and/or inefficient redox ability due to fast recombination of photogenerated electron–hole pairs.…”

Simple Preparation of Hierarchically Porous Ce/TiO2/Graphitic Carbon Microspheres for the Reduction of CO2with H2O under Simulated Solar Irradiation

“…The structural properties of all composites are shown in Table . The average diameter of graded porous composites is 13.37 nm, and much larger Brunauer–Emmett–Teller (BET) surface areas than the largest surface area of graphitic carbon composites are reported by Cai (132–204 vs 52.3 m 2 ·g –1 ). Among all composite materials, the specific surface area of 2Ce/TiO 2 /GCM was the highest, which is 204 m 2 ·g –1 .…”

Shape‐Dependent CeO2@BiOI for Degradation of Aqueous Cr(VI)

“…Cr(VI) concentration was evaluated by transferring 1 mL solution into a cuvette and checking its absorbance at 540 nm on a UV–vis spectrophotometer (the standard diphenylcarbazide method). [ 43 ] The following Equation () was adopted for the degradation efficiency (%) evaluation: where C original represents the Cr(VI) original concentration; C test represents the Cr(VI) concentration at test reaction time.…”