A highly stable metal–organic framework derived phosphorus doped carbon/Cu2O structure for efficient photocatalytic phenol degradation and hydrogen production

Abstract

Developing a low cost but efficient photocatalyst with maximum utilization of sunlight, minimum charge carrier recombination and improved stability is very crucial and challenging. Triphenylphosphine modification of HKUST-1 followed by controlled calcination resulted in a phosphorus doped carbon/Cu₂O composite (HKUST-1-P-300). The structure and band properties were fully studied, and phenol degradation and H₂ evolution were employed to evaluate the photocatalytic activity. Under visible light irradiation, HKUST-1-P-300 showed superior photocatalytic activity and stability. A phenol degradation efficiency of up to 99.8% was achieved within 90 minutes, and also a remarkable H₂ evolution rate of 1208 μmol was achieved. The external quantum efficiency of solar hydrogen evolution over this photocatalyst, without noble metal loading, reaches 48.6% at 425 nm. More auspiciously, the photocatalytic reaction continued for more than 12 h without performance degradation. To get further evidence for the origin of the improved photocatalytic activity of the HKUST-1-P-300, a series of characterization studies have been carried out. To the best of our knowledge, this work represents the first example of using P-doped carbon/Cu₂O both for phenol degradation and H₂ production. Mechanistic studies were carried out to give insights into the photodegradation process, and the superior photocatalytic activity of HKUST-1-P-300 can be ascribed to enhanced visible light absorption efficiency, higher surface area, efficient separation of photogenerated charge carriers, reduced aggregation of Cu₂O and the synergistic effect of the P-doped carbon/Cu₂O structures. This work demonstrates a facile and promising approach for designing low cost, highly stable and efficient heterostructured photocatalysts that can be applicable for energy and environmental applications.