Solution-grown 3D Cu₂O networks for efficient solar water splitting

Abstract

We report a facile and large-scale solution fabrication of cuprous oxide (Cu2O) nanowires/nanorods and 3D porous Cu2O networks and their application as photocathodes for efficient solar water splitting. The growth mechanism and structural characterization of 3D porous Cu2O networks are studied in detail. The photocathodic performance of Cu2O electrodes prepared under different growth conditions is investigated in a pH-neutral medium. The porous Cu2O network photocathodes exhibit large photocurrent, high spectral photoresponse, and incident photon-to-current efficiency compared with Cu2O nanowire/nanorod photoelectrodes. The photoelectrochemical stability of the 3D Cu2O network is significantly improved by applying multi-layer metal oxide protection.

Cu2O Photocathode with Faster Charge Transfer by Fully Reacted Cu Seed Layer to Enhance Performance of Hydrogen Evolution in Solar Water Splitting Applications

“…Both are absorption peaks by the Cu 2 O layer, verified by the bandgap (1.6 to 2.2 eV) of Cu 2 O with an absorption wavelength range from 563 to 775 nm. The obtained bandgap is in the range of reported values in the literature . Even though sample 3 and 4 have a Cu 2 O layer with similar thickness, the absorption peak by the Cu 2 O layer in sample 4 is not noticeable.…”

“…The obtained bandgap is in the range of reported values in the literature. [16][17][18] Even though sample 3 and 4 have a Cu 2 O layer with similar thickness, the absorption peak by the Cu 2 O layer in sample 4 is not noticeable. In sample 3, the absorption peak by Cu 2 O can be weakly observed (Figure 3 inset).…”

“…[10][11][12][13][14][15] Cu 2 O is a p-type semiconductor material with a band gap of 1.6-2.2 eV, absorbance in the visible light range (563-775 nm), and a suitable band edge alignment that is amenable for generating chemical energy. [16][17][18] In a PEC device, the absorbed sunlight at the Cu 2 O surface generates excited electrons by reducing protons to hydrogen gas at the interface between the photoelectrode and the electrolyte. [10,11,[13][14][15] Cu 2 O has a theoretical hydrogen conversion efficiency of 18 % in PEC cells and a power conversion efficiency of 20 % in a solar cell.…”

A novel 3D ZnO/Cu2O nanowire photocathode material with highly efficient photoelectrocatalytic performance

“…[17][18][19][20] Moreover, Cu 2 O nanowires (NWs) grown directly from Cu substrate even gives its advantages over bulk Cu 2 O such as large surface area, lower carrier recombination loss, decoupling directions of light absorption and chargecarrier collection. [21][22][23] However, the severe drawback for Cu 2 O is its low stability in aqueous solutions because the redox potentials of Cu 2 O lie within the bandgap, which limits the use of Cu 2 O as a photocathode for PEC system. [24][25][26] In the case, the Cu 2 O can be reduced to Cu, leading to a significant loss in photoactivity.…”

Semiempirical modeling of a three sublayer photoanode for highly efficient photoelectrochemical water splitting: Parameter and electrolyte optimizations

“…Many efforts were made for the direct conversion of the solar energy into the energy of chemical fuels (for instance, water reduction to H 2 ). Various semiconductor photoelectrochemical cells (PEC) for water splitting (also known as photolysis or artificial photosynthesis) have been considered: TiO 2 based cell [1], BiVO 4 [2,3], Fe 2 O 3 [4][5][6], Cu 2 O [7], CoO x [8], TiO 2 [9], dual absorber of WO 3 /Fe 2 O 3 [10] , etc. A typical PEC consists of a semiconductor photoelectrode that generates electron-hole pairs upon solar light absorption.…”