Phosphorus/oxygen co-doping in hollow-tube-shaped carbon nitride for efficient simultaneous visible-light-driven water splitting and biorefinery

The integration of photocatalytic biorefinery and water-splitting to hydrogen in one system is promising, yet limited success has been achieved. Herein, a spiral-tube-shaped carbon nitride photocatalyst (named as PACN) with phosphorus (P)/oxygen (O) co-doping was developed, which can be successfully used in the simultaneous visible-light-driven water splitting and biorefinery. The unique structure and P/O co-doping of PACN significantly enhanced the visible light absorption range and accelerated the migration/separation of photo-generated carriers. The hydrogen evolution rate over PACN reached 6437.65 μmol g -1 h −1 , which is 10.08 times higher than that of pristine carbon nitride. Meanwhile, the yield of lactic acid was as high as 93.01%. The universality of hydrogen evolution from various biomass-derived monosaccharides was demonstrated. Pentoses were more suitable for lactic acid production. Moreover, ·O 2 – played a primary role in the oxidation half-reaction. This study presents a novel co-production of hydrogen and biomass-derived chemicals that fully utilizes photocatalysis.