Electrostatic Self-Assembled Synthesis of Amorphous/Crystalline g-C3N4 Homo-Junction for Efficient Photocatalytic H2 Production with Simultaneous Antibiotic Degradation

g-C3N4has been regarded as a promising photocatalyst for photo-reforming antibiotics for H2production but still suffers from its high charge recombination, which has been proven to be solvable by constructing a g-C3N4homo-junction. However, those reported methods based on uncontrollable calcination for preparing a g-C3N4homo-junction are difficult to reproduce. Herein, an amorphous/crystalline g-C3N4homo-junction (ACN/CCN) was successfully synthesized via the electrostatic self-assembly attachment of negatively charged crystalline g-C3N4nanorods (CCN) on positively charged amorphous g-C3N4sheets (ACN). All the ACN/CCN samples displayed much higher photo-reforming of antibiotics for H2production ability than that of pristine ACN and CCN. In particular, ACN/CCN-2 with the optimal ratio exhibited the best photocatalytic performance, with a H2evolution rate of 162.5 μmol·g−1·h−1and simultaneous consecutive ciprofloxacin (CIP) degradation under light irradiation for 4 h. The UV–vis diffuse reflectance spectra (DRS), photoluminescence (PL), and electrochemical results revealed that a homo-junction is formed in ACN/CCN due to the difference in the band arrangement of ACN and CCN, which effectively suppressed the charge recombination and then led to those above significantly enhanced photocatalytic activity. Moreover, H2was generated from the water reduction reaction with a photogenerated electron (e−), and CIP was degraded via a photogenerated hole (h+). ACN/CCN exhibited adequate photostability and reusability for photocatalytic H2production with simultaneous CIP degradation. This work provides a new idea for rationally designing and preparing homo-junction photocatalysts to achieve the dual purpose of chemical energy production and environmental treatment.Keywords:H2production from wastewater;carbon nitride;homo-junction