P–N depleted bulk BiOBr/α-Fe₂O₃ heterojunctions applied for unbiased solar water splitting

Abstract

P-N depleted bulk BiOBr/α-FeO heterojunction (DBH) nanostructures with the growth of (001) BiOBr facets were prepared via a simple hydrothermal method. BiOBr possesses an average thickness of around 50 nm and shows preferential exposure of the (001) facets. α-FeO nanoparticles, with an average diameter of 5 nm, are attached on the surface of BiOBr as 20-50 nm clusters with an intimate contact interface. Such DBH nanostructures show high hydrogen evolution, and 193 mmol g of H is produced with DBH containing 1 wt% Pt, which is 6.3 times higher than that of α-FeO nanoparticles. The structural features of DBH are considered to be important to obtain attractive properties in photocatalytic water splitting.

Crystal Facet Engineering of Photoelectrodes for Photoelectrochemical Water Splitting

“…For example, BiOI/BiOCl heterojunctions with contacted facets of BiOI (001)/BiOCl (010) exhibit a higher charge injection efficiency than their counterparts with contacted facets of BiOI (001)/BiOCl (001) due to the optimized electron transfer pathway . Other faceted heterojunctions such as {001}­TiO 2 /{001}­SrTiO 3 epitaxial films, coaxial-nanocoupled SrTiO 3 /TiO 2 {001} nanotube arrays, − ultrathin g-C 3 N 4 nanosheets decorated Bi 2 MoO 6 nanosheet arrays with exposed {010} facets, α-Fe 2 O 3 modified TiO 2 {101} pyramids, {001}­BiOI@Bi 12 O 17 Cl 2 p–n junctions, {002} dominant WO 3 /BiVO 4 junctions, and {001}­BiOBr/α-Fe 2 O 3 p–n junctions also show enhanced PEC performance.…”

“…For example, BiOI/BiOCl heterojunctions with contacted facets of BiOI (001)/BiOCl (010) exhibit a higher charge injection efficiency than their counterparts with contacted facets of BiOI (001)/BiOCl (001) due to the optimized electron transfer pathway. 407 Other faceted heterojunctions such as {001}TiO 2 /{001}SrTiO 3 epitaxial films, 206 416 and {001}BiOBr/α-Fe 2 O 3 p−n junctions 417 also show enhanced PEC performance.…”

Synergistic Effect of Redox Dual PdOx/MnOx Cocatalysts on the Enhanced H2 Production Potential of a SnS/α-Fe2O3 Heterojunction via Ethanol Photoreforming

“…SnS presented S BET and pore volume values of 60.9 m 2 g –1 and 0.063 cc/g which were higher than that of α-Fe 2 O 3 with S BET and pore volume values of 24.6 m 2 g –1 and 0.031 cc/g, respectively (Figure (a)). The higher surface area of the SnS catalyst is due to its hierarchical porous architecture, whereas in the case of α-Fe 2 O 3 , a small surface area and low pore volume indicate that the α-Fe 2 O 3 primary crystals are densely packed as evidenced by TEM results . Integration of α-Fe 2 O 3 with SnS resulted in FeOSnS heterocatalysts (FeOSnS1–3) with reduced specific surface areas and pore volumes (Figure (a) and Table S1).…”

Recent Advances in Bismuth‐Based Nanomaterials for Photoelectrochemical Water Splitting

“…[116] The enhanced performance is believed to be due to migration of the electron-hole pairs in opposite directions, which remarkably suppressesr ecombination. [120] The Aurivillius phase such as Bi 2 WO 6 has also been utilized to create ah eterojunction with other wide-band-gap semiconductorst oe xtend visible-light absorption and to improve charge-carrier separation. For example, aT iO 2 and BiOCl double-layer nanostructure array has been synthesized,a nd it shows improved photocurrent and IPCE values.…”

“…[119] The BiOBr/Fe 2 O 3 bulk heterojunction shows improved H 2 evolution. [120] The Aurivillius phase such as Bi 2 WO 6 has also been utilized to create ah eterojunction with other wide-band-gap semiconductorst oe xtend visible-light absorption and to improve charge-carrier separation. In 2 O 3 is aw ide-band-gap semiconductor (3.5 eV) that has been widely used in photovoltaics and optoelectronic systemsi nh eterojunction with Bi 2 WO 6 to increasei ts PEC performance.…”