Promoting charge carrier utilization by integrating layered double hydroxide nanosheet arrays with porous BiVO4 photoanode for efficient photoelectrochemical water splitting

Abstract

The increasing exploration of renewable and clean power sources have driven the development of highly active materials for photoelectrochemical (PEC) water splitting. However, it is still a great challenge to enhance the charge utilization. Herein, we report a facile method to fabricate composite photoanode with porous BiVO4 film as the photon absorber and layered double hydroxide (LDH) nanosheet arrays as the oxygen-evolution cocatalysts (OECs). The as-prepared BiVO4/NiFe-LDH photoanode shows an excellent performance for PEC water splitting benefitting from the synergistic effect of the superior charge separation efficiency facilitated by porous BiVO4 film and the excellent water oxidation activity resulting from LDH nanosheet arrays. A photocurrent density is 4.02 mA cm −2 at 1.23 V vs. the reversible hydrogen electrode (RHE). Furthermore, the O2 evolution rate at the surface of BiVO4/NiFe-LDH photoanode is as high as 29.6 µmol h −1 cm −2 and the high activity for water oxidation is maintained for over 30 h. Impressively, the performance of the as-fabricated composite photoanode for PEC water splitting can be further enhanced through incorporating a certain amount of Co 2+ cation into NiFe-LDH as OEC. The photocurrent density is achieved up to 4.45 mA cm −2 at 1.23 V vs. RHE. This value is the highest yet reported for un-doped BiVO4-based photoanodes so far.

Co3O4 nanosheet-built hollow dodecahedrons via a two-step self-templated method and their multifunctional applications

“…On the other hand, layered double hydroxides (LDHs), which are an emerging class of lamellar functional materials with brucite-type layers, have also received great attention [18][19][20][21]. LDHs have many fascinating properties, such as large surface areas and more active sites owing to its lamellar structure.…”

Conditions for magnetic and electronic properties of ultrathin Ni–Fe hydroxide nanosheets as catalysts: a DFT+U study

“…Simultaneously, the observed difference of magnetic property guides that we can distinguish the long-range or short-range order in Ni2Fe hydroxide nanosheets by the nanoscale magnetic probe. In addition to this, recently, another attractive application of transition metal LDHs is as an excellent electrode catalyst of fuel cells [9,10,22,36]. Here the ORR/OER is employed as the probe reaction to assess the relationship between electron magnetism and electron catalysis of Ni-Fe hydroxide nanosheets.…”

Recent progress on advanced design for photoelectrochemical reduction of CO2 to fuels

“…Many n-type semiconductors are earth-abundant and intrinsically stable, especially for metal oxides [166]. In general, photoanodes are fabricated by n-type semiconductors and applied to water oxidation [25,167]. Thus it is an alternative approach to employ a photoanode to harvest light with an effective cathode for CO 2 reduction, as depicted in Fig.…”