In other words, rGO and anatase
TiO2 formed a joint electronic system. The enhancement
in photocatalytic activity could be attributed to the
combined effect of several concomitant factors. Firstly,
the band gap narrowing of the rGO-TiO2 composite
(3.2 eV→2.90 eV) allowed an enhanced absorption
of visible light. The CB of anatase TiO2 and the work
function of rGO are −4.2 eV [53] and −4.42 eV [46], respectively