Enhanced full-spectrum photocatalytic activity of 3D carbon-coated C3N4 nanowires via giant interfacial electric field

Abstract

Strong interfacial electric field can promote the separation and transfer of photogenerated carriers of photocatalysts. Herein, a three-dimensional (3D) network structure assembled from carbon-coated C3N4 nanowires (denoted as 3D C3N4@C) with a giant interfacial electric field was prepared. The unique 3D structure works with the carbon layer to expand the light absorption range of C3N4 to the full spectrum. Under visible-light irradiation (λ ≥ 420 nm), the degradation rate constants of 3D C3N4@C for bisphenol A and phenol were 41.2 and 5.7 times that of bulk g-C3N4, respectively. Meanwhile, the interfacial electric field of 3D C3N4@C-2 mol/L was 5.14 times that of bulk g-C3N4. The charge transfer process of 3D C3N4@C was confirmed by synchronous illumination X-ray photoelectron spectroscopy and DFT. The significantly improved activity was mainly ascribed to the giant interfacial electric field between g-C3N4 and the carbon layer, which significantly promoted the separation and transportation of photo-generated charge carriers.