Carbon Dot Loading and TiO₂ Nanorod Length Dependence of Photoelectrochemical Properties in Carbon Dot/TiO₂ Nanorod Array Nanocomposites

Abstract

Photoelectrochemcial (PEC) properties of TiO2 nanorod arrays (TNRA) have been extensively investigated as they are photostable and cost-effective. However, due to the wide band gap, only the UV part of solar light can be employed by TiO2. To enhance the photoresponse of TNRA in the visible range, carbon dots (C dots) were applied as green sensitizer in this work by investigating the effects of C dot loading and length of TiO2 nanorod on the PEC properties of TNRA/C dot nanocomposites. As the C dot loading increases, the photocurrent density of the nanocomposites was enhanced and reached a maximum when the concentration of the C dots was 0.4 mg/mL. A further increase in the C dot concentration decreased the photocurrent, which might be caused by the surface aggregation of C dots. A compromise existed between charge transport and charge collection as the length of TiO2 nanorod increased. The incident photon to current conversion efficiency (IPCE) of the TNRA/C dot nanocomposites in the visible range was up to 1.2-3.4%. This work can serve as guidance for fabrication of highly efficient photoanode for PEC cells based on C dots.

Dual-functional carbon dots–silver@zinc oxide nanocomposite: in vitro evaluation of cellular uptake and induction of apoptosis

“…Notably, no C-Ag or C-Zn bonds were found. This indicated that negatively charged, O-H functionalized CDs were electrostatically adsorbed on the surface of Ag@ZnO component 13,32 .…”

One-step uniformly hybrid carbon quantum dots with high-reactive TiO2 for photocatalytic application

“…In order to simply deposit CQDs on TiO 2 , 12 mg of sodium citrate was dissolved in the HF aqueous solution to form a homogeneous solution [29]. The rest procedures were the same with above.…”

Towards efficient photoinduced charge separation in carbon nanodots and TiO2 composites in the visible region

“…[9][10][11][12][13][14][15] The electron injection from CDs to TiO 2 was demonstrated to be feasible and the CD-sensitized TiO 2 photoelectrodes have been applied in photocatalysis and PVs. 10,[16][17][18][19][20][21] However, it is still a challenge to achieve efficient electron injection from CDs to TiO 2 under sunlight, 21 which is a primary photophysical process in generating photocurrent in CD-based PVs. 22,23 To date, the power conversion efficiency of CD-based PVs has been only 0.13%, as reported by Mirtchev and co-workers.…”