N,Cu-Codoped Carbon Nanosheet/Au/CuBi₂O₄ Photocathodes for Efficient Photoelectrochemical Water Splitting

Abstract

In this paper, we successfully fabricated CuBi2O4 and nitrogen,cuprum-codoped carbon nanosheet (N,Cu–C) heterostructure connected by Au nanoparticles, which was applied in photoelectrochemical (PEC) water splitting for the first time. The Au nanoparticle in situ decoration on the material surface was carried out by simple photoreduction. Owing to the plasmon resonance effect and low charge transfer resistance of Au nanoparticles, CuBi2O4/Au/N,Cu–C hybrids exhibited enhanced photocurrent compared with traditional CuBi2O4 and CuBi2O4/N,Cu–C. Typically, the as-prepared photoelectrode displayed an optimal photoelectric conversion (0.17%, at 0.4 V vs RHE) and PEC photocurrent (0.31 mA cm–2, at 100 mW cm–2 and 0.5 V vs RHE) that is about 5 times that of pure CuBi2O4. The enhanced PEC water splitting ability can be mainly attributed to the N,Cu-codoped carbon nanosheets as the passivation layer and Au nanoparticles as an electron relay for electron transport and a plasmonic photosensitizer for increased light absorption.

Rationally Designed Heterojunction on a CuBi2O4 Photocathode for Improved Activity and Stability during Photoelectrochemical Water Reduction

“…Bi 4f 7/2 (158.4 eV) and 4f 5/2 (163.7 eV) are characteristic peaks of Bi 3+ in CBO (Figure a). The binding energy peaks of Cu 2p 1/2 at 954.0 eV, Cu 2p 3/2 at 934.3 eV and the shake‐up peak at about 941–944 eV is major peak of CBO (Figure b), proving the existence of Cu 2+ . Two peaks at 529.6 eV and 531.5 eV are observed, which can be attribute to the binding energy values of lattice oxygen and oxygen vacancy in CBO and P25 as exhibited in Figure c .…”

“…The binding energy peaks of Cu 2p 1/2 at 954.0 eV, Cu 2p 3/2 at 934.3 eV and the shake-up peak at about 941-944 eV is major peak of CBO (Figure 4b), proving the existence of Cu 2 + . [16] Two peaks at 529.6 eV and 531.5 eV are observed, which can be attribute to the binding energy values of lattice oxygen and oxygen vacancy in CBO and P25 as exhibited in Figure 4c. [26] The main peaks of the above three elements are the same as the typical values of CBO.…”

“…CBO based photocathode materials for PEC HER has been developed in our group and achieved good results, such as CBO/polythiophene (PTh) and N, Cu‐codoped Carbon Nanosheets/Au/CBO . The CBO/PTh photoelectrode, the thin porous film inorganic‐organic heterostructure photocathode is constructed by the porous CBO and PTh with improved light absorption efficiency and charge separation.…”

“…CBO based photocathode materials for PEC HER has been developed in our group and achieved good results, such as CBO/polythiophene (PTh) [15] and N, Cu-codoped Carbon Nanosheets/Au/CBO. [16] The CBO/PTh photoelectrode, the thin porous film inorganic-organic heterostructure photocathode is constructed by the porous CBO and PTh with improved light absorption efficiency and charge separation. The N, Cu-codoped Carbon Nanosheets/Au/CBO photoelectrode, used Au nanoparticles as an electron relay for accelerating electron transport and a plasma photosensitizer to increase light absorption, and N, Cu co-doped carbon nanosheets as a passivation layer to improve the stability.…”

Dual Modification of a BiVO4 Photoanode for Enhanced Photoelectrochemical Performance

“…Enormous energy demand is one of the biggest challenges among the key issues we have to meet, and hydrogen is expected to be the replaceable and sustainable source to satisfy the urgent need . Photoelectrochemical (PEC) water splitting, which is driven by solar energy, is regarded as one of the most effective methods to produce large‐scale hydrogen .…”