Coupling interface constructions of NiO–Cr2O3 heterostructures for efficient electrocatalytic oxygen evolution

Oxygen Vacancies and Interface Engineering on Amorphous/Crystalline CrOx‐Ni3N Heterostructures toward High‐Durability and Kinetically Accelerated Water Splitting

“…the Raman spectra (Figure S14a, Supporting Information) for the amorphous CrO x show a similar shape with the crystalline Cr 2 O 3 , [23] but a shift from 542 to 538 cm −1 is attributed to the generation of oxygen vacancies in amorphous CrO x . Two fairly weak peaks at 512 and 732 cm −1 in Ni 3 N (Figure S14b, Supporting Information) correspond to the formation of NiO bond by the surface oxidation of Ni 3 N. [24] The Raman spectrum of the CrO x -Ni 3 N mainly contains two broad peaks. One peak located at 725 cm −1 belongs to the NiO bond and is stronger than the Ni 3 N, confirming the formation of Ni−O at the heterointerface of the CrO x -Ni 3 N. The other peak at 527 cm −1 , assigned to the mixed NiO bond and CrO bond, is much broader and weaker in intensity than the amorphous CrO x , implying that a more disordered structure of CrO x leads to more oxygen vacancies in CrO x -Ni 3 N. [17] The above experimental characterizations reveal the regulated electronic structures and numerous oxygen vacancies in the CrO x -Ni 3 N heterostructures, which agree well with the previous DFT predictions.…”

Ion Sputtering–Assisted Double‐Side Interfacial Engineering for CdIn2S4 Photoanode toward Improved Photoelectrochemical Water Splitting

“…After modification with TiO 2 layer, the photoanode possesses significantly reduced dark current density, which implies that the TiO 2 layer can effectively inhibit the backflow of electrons from FTO to CdIn 2 S 4 . After modification with NiO overlayer, the onset potential of TiO 2 /CdIn 2 S 4 /NiO shifts negatively to −0.03 V RHE , which is lower than −0.01 V RHE of TiO 2 /CdIn 2 S 4 , and 0.00 V RHE of CdIn 2 S 4 , implying that NiO overlayer can accelerate the OER dynamics . Figure b exhibits the I – t curves of CdIn 2 S 4 , TiO 2 /CdIn 2 S 4 , TiO 2 /CdIn 2 S 4 /NiO, and CdIn 2 S 4 /NiO photoanodes at 1.23 V RHE under chopped light illumination.…”

“…Then, a clean FTO glass was placed on the workbench with the conductive side upward. The ion-sputtering reaction was maintained in the glass container for different time (20,40, and 60 s) with air pressure and current keeping at 7 Pa and 5 mA, respectively. CdIn 2 S 4 was prepared by a facile CBD method: The precursor solution was prepared by dissolving 0.114 g CdCl 2 ·2.5H 2 O, 0.284 g InCl 3 ·4H 2 O, 0.301 g TAA, and 0.865 g anhydrous citric in 100 mL deionized water.…”

“…The NiO overlayer was prepared by the same magnetron sputtering method as the TiO 2 film using a Ni target by controlling the air pressure and current to 7 Pa and 15 mA, respectively. The TiO 2 /CdIn 2 S 4 sample was put into the chamber with facing upside on the workbench and the reaction was kept for different time (20,40,60, 80, and 100 s).…”

“…After modification with NiO overlayer, the onset potential of TiO 2 /CdIn 2 S 4 /NiO shifts negatively to −0.03 V RHE , which is lower than −0.01 V RHE of TiO 2 /CdIn 2 S 4 , and 0.00 V RHE of CdIn 2 S 4 , implying that NiO overlayer can accelerate the OER dynamics. [40] Figure 3b exhibits the I-t curves of CdIn 2 S 4 , TiO 2 / CdIn 2 S 4 , TiO 2 /CdIn 2 S 4 /NiO, and CdIn 2 S 4 /NiO photoanodes at 1.23 V RHE under chopped light illumination. All the samples show quick light response, and the photocurrent density values are consistent with that in J-V curves.…”