Photoelectrochemical Determination of Cu²⁺ Using a WO₃/CdS Heterojunction Photoanode

Abstract

Copper ions are not only physiologically essential for life but also hazardous materials causing a series of neurodegenerative diseases. Photoelectrochemical (PEC) detection has attracted a large amount of focus as a potential strategy to develop Cu2+ ion sensors. However, relatively low photocurrent signals with poor antidisturbance ability and the limited concentration range have prevented its practical applications. Here, we designed a WO3/CdS heterojunction photoanode for the PEC determination of Cu2+ in aqueous solution through a simple two-step chemical bath deposition method. The obtained WO3/CdS photoanode had a nanoplate morphology and showed an enhanced photoresponsivity with a photocurrent density of 1.5 mA/cm2 at 1.23 V versus RHE under illumination. Naturally, it exhibited a low detection limit (0.06 μM) and wider range (0.5 μM to 1 mM) for Cu2+ PEC detection first, suggesting that the WO3/CdS heterojunction photoanode is a promising tool to monitor copper pollution in natural environments.

Integrated Photorechargeable Energy Storage System: Next‐Generation Power Source Driving the Future

“…For example, the hexagonal‐phase tungsten oxide (h‐WO 3 ) is widely used as photoelectrocatalysis material. [ 67 ] Based on the good photoelectrocatalysis and pseudocapacitive performance, employing h‐WO 3 as a photoelectrode to realize solar energy conversion and storage is simple and direct. Zhi et al demonstrated that the capacitance of h‐WO 3 based supercapacitor can be increased by 17% under illumination ( Figure 5 a).…”

“…The nanometer‐sized and interfacial effects between different materials in the composite electrode were beneficial to enhance light absorption and promote the separation of holes–electrons pairs. [ 67,71 ] Based on this viewpoint, Ding et al designed and fabricated a nanoporous Cu@Cu 2 O (NPC@Cu 2 O) hybrid array electrode and revealed that the nanoporous Cu promoted the light permeation and enhanced energy storage. [ 72 ] The prepared photoelectrode generated electrons and holes under illumination, where the holes oxidized the Cu 2 O in the Cu@Cu 2 O hybrid to CuO, storing the holes by pseudocapacitance.…”

Research progress on photoelectrochemical sensors for contamination analysis in agricultural fields

“…75 Due to the health threats posed by high concentrations of Cu 2+ , various PEC sensors have been developed to detect Cu 2+ . 36,[78][79][80][81][82][83][84][85][86][87][88][89][90][91][92] Wang et al designed a WO3/CdS heterojunction photoanode for the PEC determination of Cu 2+ in aqueous solutions. 79 After the addition of Cu 2+ for a certain time, since both the conduction band (CB) and valence band (VB) of the CuxS generated on the surface were located near the intrinsic Fermi level of the CdS, some of the electron-hole pairs transferred to the CuxS, facilitating surface charge recombination of the WO3/CdS photoanode (Fig.…”

A facile approach to synthesize CdS–attapulgite as a photocatalyst for reduction reactions in water

“…3,32,33 As a chalcogenide photocatalyst, CdS has attracted much interest because of its narrow band gap, high light harvesting and excellent catalytic properties. [34][35][36] However, the limitations of the high recombination rate of photogenerated electron-hole pairs, photocorrosion problems, and easy agglomeration of CdS hinder its further application in photocatalysis. 34,[37][38][39] Therefore, many efforts have been made to optimize the properties of CdS such as the materials hybridization and element doping.…”

“…34,[37][38][39] Therefore, many efforts have been made to optimize the properties of CdS such as the materials hybridization and element doping. 35,40,41 Natural attapulgite (ATP) may be used as a perfect support material to hybridize with CdS because of the abundant reserves, attractive price, and special structure. And the ideal formula of the ATP is Al 2 Mg 2 Si 8 O 20 (OH) 2 (OH 2 ) 4 $4H 2 O.…”