title: High-Performance Coral Reef-like Carbon Nitrides: Synthesis and Application in Photocatalysis and Heavy Metal Ion Adsorption.
abstract: Synthesis of carbon nitrides (CNx) by refluxing under nitrogen exhibited mixed growth mechanisms of oriented attachment and Ostwald ripening, leading to the formation of coral reef-like microstructures from spherical agglomerates. Some phase transformation from β-phase to α-phase CNxoccurred upon refluxing for 1.5 h, producing a biphasic CNx. The N content relative to C was determined from CHN elemental analysis, and the presence of C═N and terminal groups (i.e., COOH and NH2) was consistent with the Fourier transform infrared, nuclear magnetic resonance, and X-ray photoelectron spectroscopic results. The sample refluxed for 2.0 h (CNx/2.0 h) had the highest surface area of 24.5 m2·g-1and displayed enhanced adsorption capacities for methylene blue (MB) molecules and heavy metal ions Pb2+(720 mg·g-1), Cd2+(480 mg·g-1), and As(V) (220 mg·g-1), which was attributed to the presence of COOH functional groups. CNxsamples had a negative surface charge that electrostatically attracted the cationic heavy metal ions as well as MB molecules for subsequent photodecomposition under visible-light illumination. The photocatalytic activity of CNx/2.0 h toward phenol, a common pollutant in aqueous waste, was also demonstrated and a possible photocatalytic route was proposed.
authors.affiliation: Particulate Fluids Processing Centre, School of Chemistry, The University of Melbourne , Melbourne, Victoria 3010, Australia.|Manufacturing, Commonwealth Scientific and Industrial Research Organization , Clayton, Victoria 3168, Australia.
authors.forename: Jeannie Z Y
authors.initials: JZ
authors.lastname: Tan
authors.affiliation: Particulate Fluids Processing Centre, School of Chemistry, The University of Melbourne , Melbourne, Victoria 3010, Australia.|Manufacturing, Commonwealth Scientific and Industrial Research Organization , Clayton, Victoria 3168, Australia.
authors.forename: Natalita M
authors.initials: NM
authors.lastname: Nursam
authors.affiliation: Manufacturing, Commonwealth Scientific and Industrial Research Organization , Clayton, Victoria 3168, Australia.|School of Engineering and Information Technology, Murdoch University , Murdoch, Western Australia 6150, Australia.
authors.forename: Fang
authors.initials: F
authors.lastname: Xia
authors.affiliation: School of Chemistry, Bio21 Institute, The University of Melbourne , Melbourne, Victoria 3010, Australia.
authors.forename: Marc-Antoine
authors.initials: MA
authors.lastname: Sani
authors.affiliation: Manufacturing, Commonwealth Scientific and Industrial Research Organization , Clayton, Victoria 3168, Australia.
authors.forename: Wei
authors.identifier: http://orcid.org/0000-0003-2802-7443
authors.initials: W
authors.lastname: Li
authors.affiliation: Manufacturing, Commonwealth Scientific and Industrial Research Organization , Clayton, Victoria 3168, Australia.
authors.forename: Xingdong
authors.initials: X
authors.lastname: Wang
authors.affiliation: Particulate Fluids Processing Centre, School of Chemistry, The University of Melbourne , Melbourne, Victoria 3010, Australia.|Manufacturing, Commonwealth Scientific and Industrial Research Organization , Clayton, Victoria 3168, Australia.
authors.forename: Rachel A
authors.identifier: http://orcid.org/0000-0003-4922-2256
authors.initials: RA
authors.lastname: Caruso
keywords: Ostwald ripening; carbon nitrides; heavy metal; oriented attachment; photocatalysis; α phase; β phase