Influence of grain size on photoelectrocatalytic performance of CuBi2O4 photocathodes

Photoelectrochemical properties of p-type CuBi2O4 prepared by spray pyrolysis of carbon-free precursor aqueous solution combined with post-annealing treatment

“…41,42,51 In contrast, the J at 0.6 V RHE generated by CBO prepared in this work is comparable to those reported CBO photoelectrodes prepared using ethanol/acetic acid-based precursor solution without organic additives together with post-annealing treatment in air (Table S5, ESI †). 40,53 Fig. 4f shows the photocurrent density-time ( J-t) curves of CBO-based photoelectrodes in the electrolyte with and without H 2 O 2 recorded at 0.6 V RHE under the illumination of continuous AM 1.5G solar light.…”

“…Surface modifications, such as the addition of a protective layer and a cocatalyst, serve as advanced strategies to prevent surface photocorrosion and promote the electron transfer process (such as the HER and CO 2 -reduction); these also mitigate photocorrosion during the PEC operation. 43,51,52,64 To further clarify the structure-activity and carrier transfer processes of CBO under light excitation, spectroscopic techniques such as photoluminescence (PL) emission spectroscopy, 40 pump-probe spectroscopy, 42 and AC impedance spectroscopy 65 should be employed. These comprehensive investigations will be performed in a future study aiming to provide an in-depth insight into the physicochemical properties of CBO and enhance its PEC energy conversion efficiency.…”

“…34,35 Among them, the CuBi 2 O 4 (CBO) material can be recognized as one of the promising candidates for the photoelectrode material for the PEC HER involving CO 2 reduction. [36][37][38][39][40][41][42][43][44][45][46][47][48] CBO has a tetragonal crystal structure and consists of stacks of square planar Cu(II)O 4 groups linked to distorted trigonal Bi(III)O 6 polyhedral groups. 34 The bandgap (E g ) energy of the CBO material has been reported to be 1.5-1.8 eV (adsorption edge wavelength up to 830 nm), 37,38,42,44 which leads to a theoretical STH energy conversion efficiency limit of B24% at an external quantum efficiency (EQE) of 100%.…”

“…[35][36][37][38][39] CBO precursor compounds have been prepared on the substrates by deposition of the precursor solution using wet processes such as electrodeposition, [36][37][38][39]49,52 drop-casting methods, 36,44,45,48,50 spin-coating methods, 46,47 and spray pyrolysis methods. [40][41][42][43]51,53 Concerning the wet process to prepare CBO-based photocathodes, most of the precursor solution is based on nonaqueous organic solvents (e.g., ethanol and dimethyl sulfoxide) and acetic acid with organic additives (e.g., polyethylene glycol (PEG) and triethyl orthoformate (TEOF)) to dissolve and stabilize the Cu and Bi complex in the solvent. 38,41,46,47 The role of the organic additives in the precursor solution is to mitigate the hydrolyzed precipitation of Bi subnitrate species as time advances in the precursor solution.…”

“…35–39 CBO precursor compounds have been prepared on the substrates by deposition of the precursor solution using wet processes such as electrodeposition, 36–39,49,52 drop-casting methods, 36,44,45,48,50 spin-coating methods, 46,47 and spray pyrolysis methods. 40–43,51,53 Concerning the wet process to prepare CBO-based photocathodes, most of the precursor solution is based on non-aqueous organic solvents ( e.g. , ethanol and dimethyl sulfoxide) and acetic acid with organic additives ( e.g.…”