Uniform carbon dots@TiO2 nanotube arrays with full spectrum wavelength light activation for efficient dye degradation and overall water splitting

Abstract

This work presents a novel approach for preparing photocatalysts based on TiO₂ nanotube arrays (TiO₂ NTAs) anchored with carbon dots (CDs) by a facile two-step method which includes an electrochemical anodization technique followed by electrochemical deposition. The synthesized high quality graphitic carbon dots can act as sensitizers to extend the spectral range of light absorption towards the full solar spectrum. It is confirmed that TiO₂ NTAs anchored with CDs (CDs/TiO₂ NTAs) display greatly improved photocatalytic activity and excellent photocatalytic stability. By tuning the light absorption of the TiO₂ NTAs, the utilization of light in charge generation and separation is well synergized with the CDs for enhanced photocatalytic pollutant degradation and water splitting, achieving significantly improved rates of photocatalytic degradation and H₂ production in the visible and full spectra, respectively.