Boosting of photocatalytic hydrogen evolution via chlorine doping of polymeric carbon nitride
Chemical doping is an effective strategy for modifying the electrochemical properties of polymeric carbon nitride and tuning its visible-light photocatalytic activity. In this study, chlorine-doped polymeric carbon nitride (Cl-PCN) has been synthesized by the polycondensation method. Among a series of samples, 200Cl-PCN exhibited the best photocatalytic activities for the hydrogen evolution from water splitting. Main aspects were revealed: (i) unique location of Cl atoms at the interlayers of PCN instead of on its π-conjugated planes, (ii) slight band gap narrowing, (iii) lower recombination rate of the electron-hole pairs, and (iv) improved photogenerated charge transport and separation. The above factors affected the 4.4-fold enhancement of photocatalytic efficiency in hydrogen evolution in comparison to the pristine catalyst.