Energy-efficient carbon-doped titanium dioxide nanoparticles: synthesis, characterization, and catalytic properties under visible LED irradiation for degradation of gemifloxacin

Synthesis and characterization of energy-efficient visible-light-responsive carbon-doped titanium dioxide nanoparticles (C-TiO2NP) is reported. The characterization results of C-TiO2NP using BET, TEM, DLS, and XRD indicate the following: (1) the C-TiO2NP have high surface area (77.02 m2/g), (2) size range of 5.00–10.00 nm and (3) zeta potential of 19 (pH 4.0), 4 (pH 7.0) and −21 (pH 10.0) while (4) the XRD results shows a peak pattern indicating that C-TiO2NP is mostly in the anatase phase. The photocatalytic properties of C-TiO2NP is investigated in this study using gemifloxacin antibiotic under LED in the visible region (λmax ~ 450 nm). Results shows that C-TiO2NP have significant catalytic properties under LED visible light (up to ~ 74% within 60 min). On the other hand, no degradation is observed for control TiO2NP using LED visible light under equivalent experimental conditions. Using control TiO2NP with H2O2 under LED visible light results in a percentage degradation of ~ 33.0%. Upon using C-TiO2NP with H2O2, the %degradation increases from ~ 33.0 to 64.0%. Although H2O2 generally enhances the activity of bare TiO2NP under UV irradiation, the %degradation under LED in the presence of C-TiO2NP and H2O2 (~ 64%) is smaller than that in the presence of C-TiO2NP only (~ 74%). Results demonstrates the applicability of C-TiO2NP as an energy-efficient and cost-effective photocatalyst under LED visible light for pharmaceutical wastewater treatment.