Phosphomolybdic Acid-Assisted Growth of Ultrathin Bismuth Nanosheets for Enhanced Electrocatalytic Reduction of CO2 to Formate

Perovskite-Derived Bismuth with I- and Cs+ Dual Modification for High-Efficiency CO2 -to-Formate Electrosynthesis and Al-CO2 Batteries

Bi-based materials are one of the most promising candidates for electrochemical CO2 reduction reaction (CO2 RR) to formate; however, the majority of them still suffer from low current density and stability that essentially constrain their potential applications at the industrial scale. Surface modification represents an effective approach to modulate the electrode microenvironment and the relative binding strength of key intermediates. Herein, it is demonstrated that the surface comodification with halides and alkali metal ions from the conversion of Bi-based halide perovskite nanocrystals is a viable strategy to boost the CO2 RR performance of Bi for formate electrosynthesis. Cs3 Bi2 I9 nanocrystals are prepared by a hot-injection method. The as-prepared products feature well-defined hexagonal shape and uniform size distribution. When used as the precatalyst, Cs3 Bi2 I9 nanocrystals are converted to Cs+ and I- comodified Bi. The resultant catalyst exhibits high formate Faradaic efficiency close to 100%, and remarkable partial current density up to 44 mA cm-2 in an H-cell and up to 276 mA cm-2 in a flow cell. Moreover, Cs3 Bi2 I9 is used as the cathode catalyst and paired with an Al anode in an Al-CO2 battery for simultaneous CO2 valorization and power generation.

Two-Dimensional Metal Nanostructures: From Theoretical Understanding to Experiment

This paper reviews recent studies on the preparation of two-dimensional (2D) metal nanostructures, particularly nanosheets. As metal often exists in the high-symmetry crystal phase, such as face centered cubic structures, reducing the symmetry is often needed for the formation of low-dimensional nanostructures. Recent advances in characterization and theory allow for a deeper understanding of the formation of 2D nanostructures. This Review firstly describes the relevant theoretical framework to help the experimentalists understand chemical driving forces for the synthesis of 2D metal nanostructures, followed by examples on the shape control of different metals. Recent applications of 2D metal nanostructures, including catalysis, bioimaging, plasmonics, and sensing, are discussed. We end the Review with a summary and outlook of the challenges and opportunities in the design, synthesis, and application of 2D metal nanostructures.

A review on bismuth-based nanocomposites for energy and environmental applications

Bismuth, a heavy metal which is found to be inexpensive and at a reduced cost, is utilized in the synthesis of different nanomaterials with novel structure, remarkable physical and chemical properties, adjustable bandgap, notable efficiency for photothermal conversion. These characteristics have made this element desirable for various applications such as storage and conversion of energy, electronics, sensors, photocatalysis, and other biomedical applications. These review papers are the vital points for the students, this report guides them to the research papers which focus on the impressive development in the area of bismuth and similar nanostructures. The purpose of the present review is to discuss the various synthesis routes of bismuth-based nanomaterials along with green synthesis, different nanostructures of bismuth, their significant properties, diverse applications and directions for the upcoming research. Therefore, with these different tuneable synthesis methods of bismuth-based nanomaterials combined with their novel properties, would elucidate on the future devices based on various nanostructures of bismuth.

Bismuth Nanosheets Derived by In Situ Morphology Transformation of Bismuth Oxides for Selective Electrochemical CO2 Reduction to Formate

Bismuth nanosheets (BiNSs) have been recognized as a promising catalyst for electrochemical CO₂ reduction (CO₂RR) to formate, but their preparation typically involves an elaborate synthesis of Bi precursors under elevated temperatures and pressures. Here, we demonstrate a simple surfactant-free method of preparing Bi₂O₃-derived BiNSs (OD-BiNSs) by aqueous precipitation and cyclic voltammetry (CV) under ambient conditions. In situ morphology transformation from Bi₂O₃ to BiNSs was observed during CV, in which the presence of oxygen and the initial morphology of Bi₂O₃ are crucial for the phase transformation. The as-prepared OD-BiNSs showed 93% of faradic efficiency (FE) to formate with a partial current density of 62 mA cm^-2 at -0.95 V_RHE in the H-cell and >94% FE at 50-200 mA cm^-2 with cell voltages of 2.4-4.0 V in the flow cell.

The inchoate horizon of electrolyzer designs, membranes and catalysts towards highly efficient electrochemical reduction of CO2 to formic acid

This review explores the recent advances in CO2 reactor configurations, components, membranes and electrocatalysts for HCOOH generation and draw readers attention to construct the economic, scalable and energy efficient CO2R electrolyzers.

Engineering the atomic arrangement of bimetallic catalysts for electrochemical CO2 reduction

The electrochemical CO2 reduction reaction (CO2RR) to form highly valued chemicals is a sustainable solution to address the environmental issues caused by excessive CO2 emissions. Generally, it is challenging to achieve high efficiency and selectivity simultaneously in the CO2RR due to multi-proton/electron transfer processes and complex reaction intermediates. Among the studied formulations, bimetallic catalysts have attracted significant attention with promising activity, selectivity, and stability. Engineering the atomic arrangement of bimetallic nanocatalysts is a promising strategy for the rational design of structures (intermetallic, core/shell, and phase-separated structures) to improve catalytic performance. This review summarizes the recent advances, challenges, and opportunities in developing bimetallic catalysts for the CO2RR. In particular, we firstly introduce the possible reaction pathways on bimetallic catalysts concerning the geometric and electronic properties of intermetallic, core/shell, and phase-separated structures at the atomic level. Then, we critically examine recent advances in crystalline structure engineering for bimetallic catalysts, aiming to establish the correlations between structures and catalytic properties. Finally, we provide a perspective on future research directions, emphasizing current challenges and opportunities.

An industrial perspective on catalysts for low-temperature CO2 electrolysis

Electrochemical conversion of CO₂ to useful products at temperatures below 100 °C is nearing the commercial scale. Pilot units for CO₂ conversion to CO are already being tested. Units to convert CO₂ to formic acid are projected to reach pilot scale in the next year. Further, several investigators are starting to observe industrially relevant rates of the electrochemical conversion of CO₂ to ethanol and ethylene, with the hydrogen needed coming from water. In each case, Faradaic efficiencies of 80% or more and current densities above 200 mA cm^-2 can be reproducibly achieved. Here we describe the key advances in nanocatalysts that lead to the impressive performance, indicate where additional work is needed and provide benchmarks that others can use to compare their results.

Electrocatalysis for CO2 conversion: from fundamentals to value-added products

This timely and comprehensive review mainly summarizes advances in heterogeneous electroreduction of CO₂: from fundamentals to value-added products.

Development of a nanoscale electroless plating procedure for bismuth and its application in template-assisted nanotube fabrication

Electroless plating is a versatile technique for the facile and controlled synthesis of metallic thin films and nanostructures. While there are numerous known procedures involving transition metals, reports on the electroless plating of post-transition metals are particularly rare, even without considering specific nanofabrication requirements. In this work we outline the development of a remarkably stable electroless plating bath for nanoscale bismuth coatings, based on the reduction of Bi–EDTA by borane dimethylamine. Its suitability for nanostructure fabrication is showcased by coating ion-track etched polycarbonate membranes, creating Bi tubes with sub-micron diameters in the process. This procedure could be particularly useful for the development and improvement of high surface-area Bi based catalysts and heavy metal sensors.

We outline the development of a remarkably stable electroless bismuth plating bath. Its nanofabrication potential is showcased by coating ion-track etched polymer membranes, enabling the synthesis of sub-micron diameter bismuth tubes.

Two-Dimensional Electrocatalysts for Efficient Reduction of Carbon Dioxide

Two-dimensional (2D) materials are attractive catalysts for the electrochemical reduction of carbon dioxide reaction (eCO₂ RR) by virtue of their tunable atomic structures, abundant active sites, enhanced conductivity, suitable binding affinity to carbon dioxide and/or reaction intermediates, and intrinsic scalability. Herein, recent advances in 2D catalysts for the eCO₂ RR are reviewed. Structural features and properties of 2D materials that contribute to their advanced electrocatalytic properties are summarized, and strategies for enhancing their activity and selectivity for the eCO₂ RR are reviewed. Prospects and challenges of applications of 2D catalysts for the eCO₂ RR on an industrial scale are highlighted.