Z-scheme CoAl-layered double hydroxide/indium vanadate heterojunction for enhanced and highly selective photocatalytic reduction of carbon dioxide to carbon monoxide

Multiflower-like ReS2/NiAl-LDH Heterojunction for Visible-Light-Driven Photocatalytic CO2 Reduction

The development of high-efficiency heterojunction photocatalysts has been recognized as an effective approach to facilitate photocatalytic CO2 reduction. In this research, we successfully synthesized a novel multiflower-like ReS2/NiAl-LDH heterojunction through a hydrothermal method. Remarkably, when exposed to visible-light irradiation, 2-ReS2/NiAl-LDH demonstrated an exceptional CO production rate of 272.26 μmol·g-1·h-1, which was 4.0 and 10.8 times higher than that of pristine NiAl-LDH and ReS2. The intertwined structure of ReS2 and NiAl-LDH promoted the efficient transfer and separation of photogenerated carriers, thereby significantly enhancing the photocatalytic CO2 reduction capabilities of the ReS2/NiAl-LDH. Furthermore, the carrier transfer pathway for the 2-ReS2/NiAl-LDH heterojunction was elucidated, suggesting a type II scheme mechanism, as evidenced by photochemical deposition experiments. The findings of this study offer valuable insights and pave the way for future research in the design and construction of LDH-based and ReS2-based heterojunctions for efficient photocatalytic CO2 reduction.

Aggregate assembly of ferrocene functionalized indium-oxo clusters

In this study, we synthesized multi-nuclear indium oxide clusters (InOCs) using 1,1'-ferrocene dicarboxylic acid (H2FcDCA) as the chelating and surface protection ligand. The obtained clusters include the cubane-type heptanuclear InOCs ([In7]) and the sandwich-type thirteen-nuclear InOCs ([In13]). Notably, [In13] represents the highest nuclear number reported within the InOC family. In addition, the presence of labile coordination sites in these clusters allowed for structural modification and self-assembly. A series of [In7] clusters with adjustable band gaps have been obtained and the self-assembly of [In7] clusters resulted in the formation of an Fe-doped dimer, [Fe2In12], and an imidazole-bridged tetramer, [In28]. Similarly, in the case of [In13] clusters, the coordinated water molecules could be replaced by imidazole, methylimidazole, and even a bridged carboxylic acid, allowing the construction of one-dimensional extended structures. Additionally, part of the H2FcDCA could be substituted by pyrazole. This flexibility in replacing solvent molecules offered diverse possibilities for tailoring the properties and structures of the InOCs to suit specific applications.

MOF-derived Co-Ni layered double hydroxides/polyethyleneimine modified chitosan micro-nanoreactor for high-efficiency capture of uranium from seawater

The preparation of powder adsorbent into microsphere adsorbent is one of the effective methods for the industrialization of uranium extraction from seawater. Herein, a MOF-derived Co-Ni layered double hydroxides/polyethyleneimine modified chitosan micro-nanoreactor (DNPM) was prepared by a simple method in this work. The microstructure and chemical structure of DNPM were comprehensively characterized. The pH value, adsorption time, initial solution concentration, temperature, competitive ions, regeneration performance, and bed column heights were investigated for the adsorption performance of DNPM by batch adsorption and fixed-bed column continuous adsorption experiments. When the contact time was 8 h, the initial concentration was 150 mg/L, and the pH value was 6, the adsorption capacity of DNPM was 334.67 mg/g. The uranium adsorption by DNPM fits with the pseudo-second-order kinetic and Langmuir models, which was a spontaneous and endothermic process. In addition, DNPM has good adsorption selectivity and reusability. The fixed-bed column continuous adsorption experiment shows that the adsorption capacity increased with the increase of bed column height. The adsorption mechanism can be attributed to coordination chelation and electrostatic interaction. In general, this work provides an effective strategy for developing environmentally friendly uranium adsorbent that can be industrially used.

A dual Z-scheme heterojunction Cu-CuTCPP/Cu2O/CoAl-LDH for photocatalytic CO2 reduction to C1 and C2 products

In this research, a ternary Cu-CuTCPP/Cu2O/CoAl-LDH composite with a dual Z-scheme heterostructure was fabricated based on a Cu2O photocatalyst and applied in photocatalytic CO2 reduction. The physicochemical properties of the prepared catalysts and the possible reaction mechanism in CO2 reduction were analyzed and studied by various characterization methods. The activity of CO2 reduction significantly increased, especially forming C2 products. The optimal yield of C2H4 and C2H6 reached 1.56 and 1.92 μmol g-1 h-1 respectively, which was 14.45 and 17.45 times that from using the Cu2O monomer. In addition, the selectivity of C2 products reached 37.4%. The satisfactory C2 yield was mainly due to the fact that Cu1+δ2(COO)3 nodes in Cu-CuTCPP contained adjacent Cu sites, which effectively promoted the C-C coupling reaction. Moreover, the dual Z-scheme heterojunction stimulated the separation of photogenerated electron-hole pairs and diminished the recombination rate. This work contributes to the development of novel photocatalysts with a dual Z-scheme heterojunction and facilitates the generation of valuable C2 products.

Ti3 C2 -modified g-C3 N4 /MoSe2 S-Scheme Heterojunction with Full-Spectrum Response for CO2 Photoreduction to CO and CH4

Energy shortage and global warming caused by the extensive use of fossil fuels are urgent problems to be solved at present. Photoreduction of CO2 is considered to be a feasible solution. The ternary composite catalyst g-C3 N4 /Ti3 C2 /MoSe2 was synthesized by hydrothermal method, and its physical and chemical properties were studied by an array of characterization and tests. In addition, the photocatalytic performance of this series of catalysts under full spectrum irradiation was also tested. It is found that the CTM-5 sample has the best photocatalytic activity, and the yields of CO and CH4 are 29.87 and 17.94 μmol g-1  h-1 , respectively. This can be ascribed to the favorable optical absorption performance of the composite catalyst in the full spectrum and the establishment of S-scheme charge transfer channel. The formation of heterojunctions can effectively promote charge transfer. The addition of Ti3 C2 materials provides plentiful active sites for CO2 reaction, and its superior electrical conductivity is also favorable for the migration of photogenerated electrons.

SiC@FeZnZiF as a Bifunctional Catalyst with Catalytic Activating PMS and Photoreducing Carbon Dioxide

Herein, we encapsulated modified silicon carbide nanoparticles utilizing a metal-organic backbone. E-SiC-FeZnZIF composites were successfully prepared via Fe doping. The catalysis activity of this bifunctional composite material was evaluated by the degradation of tetracycline (THC) and carbamazepine (CBZ) and the reduction of carbon dioxide (CO₂). Nano SiC has received widespread attention in advanced oxidation applications, especially in the catalytic activation of peroxymonosulfate (PMS). However, the inferior activity of SiC has severely restricted its practical use. In this study of dual functional composite materials, nano SiC was firstly etched under aqueous alkali. Then, zeolite imidazolate frame-8 (ZIF-8) was used for immobilization. The filling of the etched nano SiC with FeZnZiF was confirmed by SEM, XRD, FTIR, BET, and XPS analyses. In addition, E-SiC-FeZnZIF exhibited excellent catalytic activation of peroxymonosulfate (PMS) to oxidize water pollutants, which can degrade tetracycline hydrochloride (THC), achieving a removal rate of 72% within 60 min. Moreover, E-SiC-FeZnZIF exhibited a relatively high CO₂ reduction rate with H₂O. The yields of CO and CH₄ were 0.085 and 0.509 μmol g^-1, respectively, after 2 h, which are higher than that of 50 nm of commercial SiC (CO: 0.084 μmol g^-1; CH₄: 0.209 μmol g^-1). This work provides a relatively convenient synthesis path for constructing metal skeleton composites for advanced oxidation and photocatalytic applications. This will have practical significance in protecting water bodies and reducing CO₂, which are vital not only for maintaining the natural ecological balance and negative feedback regulation, but also for creating a new application carrier based on nano silicon carbide.

Rational Construction of Metal Organic Framework Hybrid Assemblies for Visible Light-Driven CO2 Conversion

Photocatalytic reduction of CO₂ to value-added chemicals is known to be a promising approach for CO₂ conversion. The design and preparation of ideal photocatalysts for CO₂ conversion are of pivotal significance for the sustainable development of the whole society. In this work, we integrated two functional organic linkers to prepare a novel metal organic framework (MOF) photocatalyst {[Co(9,10-bis(4-pyridyl)anthracene)_0.5(bpda)]·4DMF} (Co-MOF). The existence of anthryl and amino groups leads to a wide range of visible light absorption and efficient separation of photogenerated electrons. To extend the lifetime of photogenerated electrons in the photocatalytic system, we modified Co-MOF particles onto g-C₃N₄. As expected, Co-MOF/g-C₃N₄ composites exhibited an ultrahigh selectivity (more than 97%) in the photocatalytic process, and the highest CO production rate (1824 μmol/g/h) was 7.1 and 27.2 times of Co-MOFs and g-C₃N₄, respectively. What's more, we also discussed the reaction mechanism of the Co-MOF/g-C₃N₄ photocatalytic CO₂ reduction, and this work paves the pathway for designing photocatalysts with ideal CO₂ reduction performance.