The photocatalytic degradation of sodium diclofenac in different water matrices using g-C3N4 nanosheets: A study of the intermediate by-products and mechanism

Photocatalytic hydrogen generation from a methanol–water mixture in the presence of g-C3N4 and graphene/g-C3N4

“…60 E CB = χ – E C − 0.5 E g where, E CB is the conduction band potential, the χ is the absolute electronegativity of the semiconductor, E C is the energy of the free electron on the hydrogen scale (approximately 4.5 eV), 61 and E g is the band gap energy of the semiconductor. The valence band potential can be calculated from E VB = E CB − E g , the χ value of g-C 3 N 4 is 4.73 eV, 62 and the relationship between E NHE (NHE = normal hydrogen electrode) and E AVS (where AVS = absolute vacuum scale) is: 63 E AVS = E NHE − E C The positions of the semiconductor's electronic band edge with respect to water oxidation/reduction potential levels are critical in determining the feasibility of photocatalytic H 2 production. To this end, the conduction band bottom (CB) must be more negative than the reduction band bottom (H + /H 2 ), while the valence band top (VB) must be more positive than the oxidation band bottom (H 2 O/O 2 ).…”

Photocatalytic Degradation of Fluoroquinolone Antibiotics in Solution

“…where ECB and EVB are the edge potentials of the valence band (VB) and conduction band (CB), respectively, X is the absolute electronegativity, EC is the energy of free electrons on the hydrogen scale (4.50 eV) [59,60], and Eg is the bandgap. X values for ZnO and gC3N4 are 5.75 [61] and 4.73 eV [62], respectively. The calculated ECB and EVB edge positions for Au@ZnONPs are -0.355 and 2.855 eV, respectively, while for gC3N4 the calculated values were -1.165 and 1.625 eV, respectively, being in agreement with values previously determined in other investigations [62,63].…”

“…X values for ZnO and gC3N4 are 5.75 [61] and 4.73 eV [62], respectively. The calculated ECB and EVB edge positions for Au@ZnONPs are -0.355 and 2.855 eV, respectively, while for gC3N4 the calculated values were -1.165 and 1.625 eV, respectively, being in agreement with values previously determined in other investigations [62,63]. Under visible radiation (Figure 9), the electrons of the VB of gC3N4 are excited towards the conduction band (CB), giving rise to h + in the VB.…”

Comparison of Different Advanced Oxidation Processes (AOPs) and Photocatalysts for the Degradation of Diclofenac

“…[34,35] Indeed, the measured absorbance increased up to 20 % after 3 h, which sounds counter intuitive for this process if we do not think about the formation of species that absorb more effectively at the selected wavelength. [35][36][37] A further test was done with stoichiometric addition of hydrogen peroxide, which is equal to 0.8 mL of 35 % H 2 O 2 per 100 mg of DCF. The most efficient treatment was the one with immersed UV lamp, resulting in 89 % conversion, as illustrated in Figure 8.…”