Influence of CVD parameters on Co‐TiO2/CNT properties: A route to enhance energy harvesting from sunlight

Abstract

AbstractCarbon nanotubes (CNTs) have been employed to enhance the photoactivity of titanium dioxide (TiO2). In this work, CNTs were deposited by chemical vapor deposition (CVD) onto the surface of anodized Co‐TiO2 nanotubes. The influence of CVD parameters (time and temperature) on the Co‐TiO2/CNT structure and properties was investigated. We studied three synthesis times (10, 20, and 30 min) and two synthesis temperatures (700 and 800°C). The samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, and X‐ray diffraction (XRD). The photocurrent performance of the electrodes was determined by linear voltammetry. The results showed the successful formation of Co‐TiO2/CNT hybrid structures. The shortest synthesis time produced higher quality CNTs. The samples synthesized at 700 and 800°C for 10 min exhibited a current density of 1.13 mA.cm−2 and 7.84 mA.cm−2, respectively, which is 9 and 65 times greater than the Co‐TiO2 sample. The synergistic effect of the CNT deposition and the crystalline phase composition significantly improved the photoresponse of TiO2. The proper choice of synthesis parameters allowed the control of the sample structure, leading to the production of electrodes with better light‐harvesting performance.