Synthesis, Characterization, and Synergic Photocatalytic Activity of Amorphous TiO2/Chitosan Carbon Microspheres

Abstract

In this work, we report the synthesis and characterization of new amorphous graphene-like TiO 2 / chitosan carbon microspheres and its performance as photocatalyst. Four different carbon chitosan microspheres materials were obtained based on the distinctive procedure to incorporate TiO 2 and TiOSO 4 to chitosan structure by pyrolysis at 600 °C. Detailed characterizations were carried out using many different techniques, as thermogravimetric analysis/differential scanning calorimetry (TGA/DSC), scanning electron miscroscopy/energy dispersive X-ray spectroscopy (SEM/EDS), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), N 2 adsorption-desorption, and the obtained materials show an amorphous and a graphene-like structure, which improve the photocatalytic activity. The synthesized materials promoted a fast degradation of three micropollutants under UV-A radiation and, in all cases the degradation rate was approximately 98% at 30 min of reaction, being superior to the P-25 TiO 2 efficiency. Due to the amorphous graphene-like structure, all the materials present low adsorption capacity, the high photocatalytic efficiency can be attributed to the material structure that promotes the effective charge separation which reduces the recombination electron/hole, enhancing the photocatalytic efficiency.

Crystallinity Modulation of Electron Acceptor in One‐Photon Excitation Pathway‐Based Heterostructure for Visible‐Light Photocatalysis

“…The O 1s spectrum of TiO 2 includes three peaks at 530.4, 532.0, and 533.4 eV, which represent the TiO bond lattice, OH bond peak [ 42,43 ] and crystal water within the precursor. [ 44 ] The peaks of Ti‐O, OH and crystal water also exist in CCN/TiO 2 ‐L. The new peak of C‐O‐Ti at 531.7 eV can be detected for CCN/TiO 2 ‐L, [ 45 ] confirming the formation of bridging bonding in the heterostructure that can enable electrons transfer from CCN to TiO 2 .…”