Electrochemical Deposition of MgO@ZnO Shell−Core Nanorod Arrays Largely Enhances the Photoelectrochemical Water Splitting Performance

Abstract

Well aligned ZnO nanorod array (NRA) core coated with MgO nanolayer shell was fabricated via a facile pulse electrodeposition method. Using this method, a homogeneous MgO nanolayer could be formed on the surface of the wurtzite ZnO nanorod. This novel nanostructure with controllable shell thickness, provided a high photoinduced current density of 2.4 mA cm−2 at 1 V (vs. Ag/AgCl) under 100 mW cm−2 illumination (AM 1.5), which value is almost three times larger than that of pristine ZnO NRA and also much superior to those of analogous ZnO based photoanodes. The as‐prepared photoanodes exhibited excellent behaviors in photoelectrochemical (PEC) water splitting, significantly improved the photoconversion efficiency. This is attributed to the interface effect and surface hydrophilia provided by the MgO ultrathin nanolayer, suppressing the recombination rate of electron‐hole pairs and improving interfacial charge exchange capacity. Thus, this work provides a cost‐effective route to improve the performance of ZnO based photoanodes, in addition it can be used in other solar energy conversion devices, for example, this hydroxyl groups dominant surface can be employed for other visible light response semiconductors (CdS, CdTe etc.) assembly.

An MgO passivation layer and hydrotalcite derived spinel Co2AlO4 synergically promote photoelectrochemical water oxidation conducted using BiVO4-based photoanodes

“…3f), the peak at 1303.9 eV indicates the existence of MgO nanolayers. 46 The XPS images of BiVO 4 , MgO/BiVO 4 and Co 2 AlO 4 /BiVO 4 are shown in Fig. S5 †.…”

“…3f ), the peak at 1303.9 eV indicates the existence of MgO nanolayers. 46 The XPS images of BiVO To evaluate the optical properties of each electrode, we conducted the UV-Vis diffuse reflectance test. The absorption intensity of the MgO/BiVO 4 , Co 2 AlO 4 /BiVO 4 and Co 2 AlO 4 /MgO/ BiVO 4 electrodes is significantly higher than that of BiVO 4 , while the absorption edge has no obvious change (Fig.…”

InGaN Nanorods Decorated with Au Nanoparticles for Enhanced Water Splitting Based on Surface Plasmon Resonance Effects

“…Compared with their bulk and film, low-dimensional structures have a larger active area and lower light reflectivity, which can strengthen light absorption [3,9,10]. Surface band bending is also beneficial for improving carrier separation efficiency and reducing the recombination probability during migration [11,12]. Furthermore, the transmission distance of photogenerated carriers to the semiconductor-electrolyte interface will be greatly reduced with a lower-dimensional structure [13,14].…”

Enhanced Photoelectrocatalytic H2 Evolution over Two‐Dimensional MoS2 Nanosheets Loaded on Cu‐Doped CdS Nanorods

“…Nowadays, more and more attention has been paid to photoelectrocatalytic materials such as WO 3 , CdS, ZnO and so on. CdS is widely used in the field of photocatalysis due to the suitable band gap of 2.4 eV, which enables it has a good performance of visible light absorption.…”