Based on this principle, we selected a CDs photocatalyst synthesized with secondary amine dopants (Fig. ). The incorporation of these amines leads to the formation of alkyl ammonium cations on the CDs surface during hydrothermal carbonization, thereby elevating the oxidation potential of the CDs catalyst (CD-1 hereafter). Upon 400 nm excitation, CD-1 photocatalyst shown strong broad emission peak centered at 465 nm which corresponds to an optical band gap of 2.67 ev (fig. ). Cyclo-voltametry studies confirmed CD-1 possesses reduction potentials of E 1 2 ⁄ red = 1.14 V versus the saturated calomel electrode (SCE), which would satisfy the desired reductive quenching via oxidation of thiol (E 1 2