Fabrication of PANI-TiO2/rGO hybrid composites for enhanced photocatalysis of pollutant removal and hydrogen production

Abstract

A hybrid composite material was fabricated by functionalizing rGO surface with TiO2 and attaching it to polymerized aniline to obtain a photocatalyst with a very efficient charge separation. The resulting PANI-TiO2/rGO photocatalysts were very thoroughly characterized using X-ray diffraction (XRD), Raman spectra, Fourier transform infrared spectra (FTIR), UV–vis diffuse reflectance spectra, scanning electron microscopies (SEM), transmission electron microscopies (TEM), and X-ray photoelectron spectroscopy (XPS). TiO2 nanoparticles dispersed in rGO did not alter its structure. PANI-covered with rGO showed an improved charge separation efficiency. Our novel PANI-TiO2/rGO photocatalysts showed narrower bandgap energy and increased ability to absorb light in the visible region. The H2 production rate and the photodegradation efficiency of Rhodamine B (RhB) were 0.806 mmol h−1 g−1 and 90.5%, respectively, which were 1.8 and 10.1 times higher than the same values obtained under the assistance TiO2/rGO and TiO2 photocatalysts. The photocatalytic mechanism is also studied. Improvement in the photocatalytic performance can be attributed to the synergy between rGO, TiO2, and PANI, which allowed for an extended spectral response as well as for enhanced separation of photogenerated charge carriers. This work provides an effective method to develop photocatalytic systems for applications related to environmental pollution and hydrogen production.