Ultrasound‐Triggered Surface Reconstruction with Improved Carriers Transfer Kinetics in CdIn₂S₄ for Solar Water Oxidation

Abstract

The surface oxygen evolution reaction (OER) is severely restricted owing to the sluggish OER kinetics and limited number of reactive sites. Although surface reconstruction can introduce defects to improve the OER performance, they often function as recombination centers and cause severe carrier recombination. With the aid of ultrasonication, the CdIn2S4 photoanode surface is reconstructed using Zn‐modified Cd defects without extreme chemical reaction environment. Owing to the surface reconstruction, the formed type‐II band structure is beneficial for separating photogenerated carriers and reduced the bulk recombination. Additionally, the Zn‐modified Cd defects are introduced in situ during the ultrasound cavitation process, which facilitated the carrier transfer, reduced the surface recombination, and increased the number of surface active sites. First‐principles calculations indicate that the modified Cd defects effectively lower the electrochemical reaction barrier and promote the surface OER kinetics by precisely regulating the four‐electron reaction. Consequently, the optimized photoanode exhibits a enhanced photocurrent of 5.30 mA cm−2 at 1.23 V versus reversible hydrogen electrode. These results demonstrate that an accurate surface reconstruction design can be achieved for introducing and modifying metal defects to improve the transfer and transport behaviors of photogenerated carriers.

Engineering Charge Separation in α-Ga2O3 Nanorod Arrays for Photoelectrochemical UV Detection

“…When Na 2 SO 3 was used as the reaction solution, surface recombination is basically suppressed and η surf could be considered as a unit. Therefore, the photocurrent density measured in Na 2 SO 3 is defined as J normalN normala 2 SO 3 = J normala normalb normals normalo normalr normalb normale normald × η normalb normalu normall normalk In this case, η surf and η bulk can be expressed according to eqs and above − η normals normalu normalr normalf = J H 2 normalO / J normalN normala 2 SO 3 η normalb normalu normall normalk = J normalN normala 2 SO 3 / J normala normalb normals normalo normalr normalb normale normald Since J absorbed is defined as the current density when absorbed photons are fully converted to current, the absorbed photon–current conversion efficiency of the samples can be approximated to be 100% . The integrated photocurrent density was obtained by integrating the product of the light-harvesting efficiencies (LHEs) (Figure S9a) of the samples with the relative spectral power of the LED (255 nm, 2 mW cm –2 ) , J normala normalb normals = …”

“…When Na 2 SO 3 was used as the reaction solution, surface recombination is basically suppressed and η surf could be considered as a unit. Therefore, the photocurrent density measured in Na 2 SO 3 is defined as In this case, η surf and η bulk can be expressed according to eqs and above − Since J absorbed is defined as the current density when absorbed photons are fully converted to current, the absorbed photon–current conversion efficiency of the samples can be approximated to be 100% . The integrated photocurrent density was obtained by integrating the product of the light-harvesting efficiencies (LHEs) (Figure S9a) of the samples with the relative spectral power of the LED (255 nm, 2 mW cm –2 ) , where e is the electron charge, h is Planck’s constant, c is the speed of light, λ is the wavelength, I λ is the relative spectral power of the LED, and LHE λ is light-harvesting efficiencies of the samples.…”

CoOOH/CdIn2S4 film photoanodes driving unbiased tandem cells towards simultaneous efficient oxidation of benzyl alcohol and selective generation of ethanol from CO2 reduction

“…[30][31][32] Based on the advantages of transition metal sulde photoanodes and co-catalysts, transition metal sulde photoanodes further combined with suitable co-catalysts are expected to achieve the oxidation of alcohol with high selectivity and stability. [33][34][35] Accordingly, it is worth developing effective co-catalysts/transition metal sulde photoanodes and investigating their reaction mechanism to construct unbiased tandem cells with Cu 2 O-based cathodes for the simultaneous achievement of CO 2 reduction and alcohol oxidation to produce valuable products.…”