Bi₁₂O₁₇Cl₂ with a Sextuple BiO Layer Composed of Rock‐Salt and Fluorite Units and its Structural Conversion through Fluorination to Enhance Photocatalytic Activity

Abstract

Layered bismuth oxyhalides with bilayered (Bi 2 O 2 ) fluorite (FL) slabs are promising visible-light photocatalysts because of their excellent stability and the ability to adjust band levels depending on the layers combined. It is interesting to manipulate the Bi 2 O 2 slab itself, but only trilayered FL blocks (e.g., Bi 3 O 4 ) are reported so far. Here, a structurally uncharacterized Bi 12 O 17 Cl 2 , which is extensively studied as a photocatalyst for a variety of reactions, has a sextuple Bi 6 O 8.5 block separated by Cl is shown. Unlike double and triple layered cases, the inner region of the Bi 6 O 8.5 block contains 1D rock-salt (RS) units in the FL matrix along the a-axis, causing in-plane corrugation. A topochemical reaction involving anion-exchange gives Bi 12 O 17-0.5x F x Cl 2 (x ≤ 6) with alternate FL and RS slabs along the c-axis. The elimination of the structural corrugation increases higher photo-conductivity and improves photocatalytic activity against acetic acid decomposition under visible light irradiation. This study paves new opportunities of controlling the properties of layered bismuth oxyhalides by the thickness of Bi-O block, FL/RS configuration, and structural modulation.

Tunable Interfacial Charge Transfer in a 2D–2D Composite for Efficient Visible‐Light‐Driven CO2 Conversion

“…Such a phenomenon cannot be observed on the high-resolution Mo 3d spectra of the prepared samples (Figure S11d, Supporting Information), suggesting that the influences of the OVs and bismuthene mainly reflect on the Bi and O elements of BMO. [32] To further investigate the influence of the OVs and bismuthene on the photogenerated charge carrier of the BMO, we perform the in situ XPS characterization (Figure 3). According to the working principle of XPS, the increase in the electron density of a specific element can result in a decrease in its corresponding binding energy value.…”

Synthesis of Co3O4 Nanoparticles-Decorated Bi12O17Cl2 Hierarchical Microspheres for Enhanced Photocatalytic Degradation of RhB and BPA

“…These nanosheets formations could potentially have occurred due to the bonding of the OH functional group to Bi 3+ ions in Cl–Bi–O–Bi–Cl complex, which grew vertically along the c axis due to its intrinsic crystal structure. Since BOC has a known silane-type structure with a space group of P4/nmm and lattice constants of a = 5.4 Å and c = 35.20 Å, which are related to √2a s × √2b s × c s supercell, its layered structure was constructed through the combination of the 6-fold metal-oxygen (Bi-O) layer separated by the Cl layer [ 50 ]. Therefore, the formation of the nanosheets and their regulation with the OH functional group were considered to be favorable [ 51 ].…”

Combined Analyses on Electronic Structure and Molecular Orbitals of d10 Bimetal Oxide In2Ge2O7 and Photocatalytic Performances for Overall Water Splitting and CO2 Reduction

“…The development of sustainable energy and reducing the greenhouse gas in the atmosphere are the very hot topics at present to solve the emerging worldwide challenges of oil shortage and continual temperature increase. − Semiconducting photocatalysis is a plausible solution to both issues, i.e. photocatalytic overall water splitting into H 2 /O 2 , and photocatalytic reduction of CO 2 into CO, CH 4 or CH 3 OH. − Research in the field of heterogeneous photocatalysis include developing novel single-phase or composite photocatalysts, understanding the photocatalytic process, and elevating the quantum efficiency. − The hitherto single-phase photocatalysts capable of overall water splitting are still in a small number comparing to the composite ones, because they should satisfy not only the thermodynamics requirements for overall water splitting but also the kinetics requirements for two half reactions of H 2 /O 2 production. ,, The photodriven reduction of CO 2 involves the gas molecule adsorption and the reactions with multiple-electron transitions, either into CO or other products; thus the photocatalytic mechanism is quite complicated and people are still working on developing highly efficient photocatalysts. − …”

“…Some pioneering works suggest the contribution from the outer s orbitals of p-block metal cations is beneficial to the highly dispersive conduction band minimum (CBM), thus leading to the high mobility of the electrons, in comparison with the d 0 transition metal cations. 33−35 Thus, a series of oxides containing d 10 33−40 In some cases, the distorted metal−oxygen tetrahedra or octahedra can also generate local dipole moments, driving the separation of the photogenerated charges. In addition, the d 10 bimetal oxides ZnGa 2 O 4 and Zn 2 GeO 4 are also well-known photocatalysts for CO 2 reduction.…”

“…Accordingly, a simple principle can be proposed that d 10 metal containing oxides with continued covalent network might be good candidates to photocatalysts, and in the meantime, the combined analyses on covalent bonds and electronic structure are helpful to understand the mechanism of the photocatalysis, guiding the further modifications based on structure−property relationships. With such a rationale, we choose the d 10 bimetal oxide In 2 Ge 2 O 7 as the target.…”