Morphology of ZnO triggered versatile catalytic reactions towards CO2 fixation and acylation of amines at optimized reaction conditions

Al Foil-Supported Carbon Nanosheets as Self-Supporting Electrodes for High Areal Capacitance Supercapacitors

Self-supporting electrode materials with the advantages of a simple operation process and the avoidance of the use any binders are promising candidates for supercapacitors. In this work, carbon-based self-supporting electrode materials with nanosheets grown on Al foil were prepared by combining hydrothermal reaction and the one-step chemical vapor deposition method. The effect of the concentration of the reaction solution on the structures as well as the electrochemical performance of the prepared samples were studied. With the increase in concentration, the nanosheets of the samples became dense and compact. The CNS-120 obtained from a 120 mmol zinc nitrate aqueous solution exhibited excellent electrochemical performance. The CNS-120 displayed the highest areal capacitance of 6.82 mF cm-2 at the current density of 0.01 mA cm-2. Moreover, the CNS-120 exhibited outstanding rate performance with an areal capacitance of 3.07 mF cm-2 at 2 mA cm-2 and good cyclic stability with a capacitance retention of 96.35% after 5000 cycles. Besides, the CNS-120 possessed an energy density of 5.9 μWh cm-2 at a power density of 25 μW cm-2 and still achieved 0.3 μWh cm-2 at 4204 μW cm-2. This work provides simple methods to prepared carbon-based self-supporting materials with low-cost Al foil and demonstrates their potential for realistic application of supercapacitors.

Constructing a metal-free 2D covalent organic framework for visible-light-driven photocatalytic reduction of CO2: a sustainable strategy for atmospheric CO2 utilization

A 2D polyimide-linked covalent organic framework (COF) with band gap energy of 2.2 eV is developed as a stable and efficient porous photocatalyst which shows CO2 reduction to formic acid, formaldehyde and methanol.

Zn(II)-Functionalized COF as a Recyclable Catalyst for the Sustainable Synthesis of Cyclic Carbonates and Cyclic Carbamates from Atmospheric CO2

A simple covalent organic framework (COF) bearing β-ketoenamine units as a potential heterogeneous ligand for ZnII-catalyzed fixation and transformation of CO2 into value-added chemicals is reported. Catalytic investigations convincingly demonstrated...

Synergetic effect of ZnCo2O4/inorganic salt as a sustainable catalyst system for CO2 utilization

Currently, it is essential to consider the rapidly increasing emission of CO₂ into the atmosphere, causing major environmental issues such as climate change and global warming. In this work, we have developed the binary catalyst system (ZnCo₂O₄/inorganic salt) for chemical fixation of CO₂ with epoxides into cyclic carbonates without solvent, and all reactions were performed on a large scale using a 100 ml batch reactor. Two mesoporous catalysts of ZnCo₂O₄ with different architecture, such as flakes (ZnCo-F) and spheres (ZnCo-S) were synthesized and utilized as a heterogeneous catalyst for cycloaddition reaction. The bifunctional property of catalysts is mainly attributed to strong acidic and basic properties confirmed by TPD (NH₃ & CO₂) analysis. The ZnCo-F catalyst exhibited excellent conversion of propylene oxide (99.9%) with good corresponding selectivity of propylene carbonate (≥99%) in the presence of inorganic salt (KI) at 120 °C, 2 MPa, 3 h. In addition, ZnCo-F catalyst demonstrated good catalytic applicability towards the various substrates scope of the epoxide. Furthermore, the catalytic properties were examined by evaluating the reaction parameter such as catalyst loading, pressure, temperature and time. The proposed catalyst exhibited good reusability for cycloaddition reaction without significant change in its catalytic activity and proposed a possible reaction mechanism for chemical fixation of CO₂ with epoxide into cyclic carbonate over ZnCo-F/KI.