Photoelectrochemical hydrogen production at peak efficiency over 10% via PbSe QDs/TiO2 nanotube array photoanodes

Abstract

Modulating the deposition of quantum dots onto TiO2 nanotube arrays provides an effective approach for expansion of visible light response, enhancement of separation and interfacial transfer of photoinduced charge carries, and improvement of photoconversion efficiency. In this paper, titanium dioxide nanotube arrays (TNAs) were modified with PbSe quantum dots (QDs) through the successive ionic layer adsorption and reaction (SILAR) under nitrogen to prepare PbSe/TNAs photoanodes. XRD, SEM, HR-TEM, UV–Vis–NIR DRS, PL, XPS, EIS, Tafel plots, Mott–Schottky analyses and J–V characteristics were used to characterize the samples. The deposition of PbSe QDs was tuned by varying the Se/Pb atomic ratios during the SILAR process. Energy band configuration, interfacial contact characteristics and photoelectrochemical properties were dissected and optimized. At the Se/Pb ratio of 5, the sample (5)PbSe/TNAs demonstrated excellent photoelectrochemical performance with a short circuit photocurrent density of 15.45 mA cm−2 and a corresponding photoconversion efficiency of 10.6%.