Effective photocatalysis of functional nanocomposites based on carbon and TiO2 nanoparticles

Abstract

A unique nanocomposite C-TiO2 was prepared by the growth of TiO2 on carbon nanoparticles using a simple hydrothermal procedure. Transmission electron microscopic (TEM) measurements showed that the nanocomposites exhibited an average core diameter of approximately 5 nm with a rather well-defined lattice space (0.4 nm) that was somewhat larger than that (0.38 nm) of the (100) crystalline planes of anatase TiO2. This lattice expansion was accounted for by the formation of surface defect dipoles of the nanosized TiO2 particles. X-ray photoelectron spectroscopic (XPS) measurements suggested that partial charge transfer occurred from carbon nanoparticles to TiO2 by the interfacial Ti-O-C linkages, which led to effective diminishment of the C-TiO2 photoluminescence as compared to that of pure TiO2 or carbon nanoparticles, suggesting intimate electronic interactions between the carbon and TiO2 components in the nanocomposites. Such unique characteristics were then exploited for the effective photocatalytic degradation of organic pollutants, as exemplified by methylene blue, by C-TiO2 under UV photoirradiation. Experimental measurements showed that the photocatalytic activity of C-TiO2 nanocomposites was about twice that of TiO2 alone, whereas little activity was observed with carbon nanoparticles. This was attributed to the electron-accepting sites on the carbon nanoparticles that facilitated interfacial charge separation.

Preparation and characterization of titanium dioxide modified with carbon with enhanced photocatalytic activity

“…Diffractograms of all powders show intensive peaks which belong to anatase phase ( Fig. 1 b) as in works [1,3,4]. No signal of brookite or rutile is detected by XRD.…”

“…The UV-Vis spectra reveal that the pure TiO 2 exhibit an absorption edge around 380 nm, the composite samples extended the absorption to the visible range (around 420 nm). This may indicate that carbon and TiO 2 nanoparticles are integrated to form C/TiO 2 nanocomposites [4]. Modification of titanium with carbon leads to band gap narrowing of composites (Fig.…”

“…The authors [4] suggested that partial charge transfer occurred from carbon nanoparticles to TiO 2 by the interfacial Ti-O-C linkages and the electron-accepting sites on the carbon nanoparticles facilitate interfacial charge separation.…”

Investigation of nitrogen doped and carbon species decorated TiO2 with enhanced visible light photocatalytic activity by using chitosan

“…S9). However, the low contrast and poor crystallinity as compared to TiO 2 make it not exactly resolved in HRTEM image [48].…”

Synthesis of grape-like carbon nanospheres and their application as photocatalyst and electrocatalyst

“…Photocatalytic degradation efficiency of CNS for MB is 65% in 300 min. However, the degradation efficiency of bare CNS is low, but it is much higher than that of reported for carbon nanoparticles (CNPs) [40]. After four hours of UV-light irradiation, about 43% of MB was degraded by CNS while only little activity was observed by Lin et al [40] for CNPs under same conditions.…”