A systematic review on the state-of-the-art and research gaps regarding inorganic and carbon-based multicomponent and high-aspect ratio nanomaterials

This review explores the state-of-the-art with respect to multicomponent nanomaterials (MCNMs) and high aspect ratio nanomaterials (HARNs), with a focus on their physicochemical characterisation, applications, and hazard, fate, and risk assessment. Utilising the PRISMA approach, this study investigates specific MCNMs including cerium-zirconium mixtures (CexZryO2) and ZnO nanomaterials doped with transition metals and rare earth elements, as well as Titanium Carbide (TiC) nanomaterials contained in Ti-6Al-4V alloy powders. HARNs of interest include graphene, carbon-derived nanotubes (CNTs), and metallic nanowires, specifically Ag-based nanowires. The review reveals a significant shift in research and innovation (R&I) efforts towards these advanced nanomaterials due to their unique properties and functionalities that promise enhanced performance across various applications including photocatalysis, antibacterial and biomedical uses, and advanced manufacturing. Despite the commercial potential of MCNMs and HARNs, the review identifies critical gaps in our understanding of their environmental fate and transformations upon exposure to new environments, and their potential adverse effects on organisms and the environment. The findings underscore the necessity for further research focused on the environmental transformations and toxicological profiles of these nanomaterials to inform Safe and Sustainable by Design (SSbD) strategies. This review contributes to the body of knowledge by cataloguing current research, identifying research gaps, and highlighting future directions for the development of MCNMs and HARNs, facilitating their safe and effective integration into industry.

Dielectric Barrier Discharge Plasma-Assisted Catalytic CO2 Hydrogenation: Synergy of Catalyst and Plasma

CO2 hydrogenation is an effective way to convert CO2 to value-added chemicals (e.g., CH4 and CH3OH). As a thermal catalytic process, it suffers from dissatisfactory catalytic performances (low conversion/selectivity and poor stability) and high energy input. By utilizing the dielectric barrier discharge (DBD) technology, the catalyst and plasma could generate a synergy, activating the whole process in a mild condition, and enhancing the conversion efficiency of CO2 and selectivity of targeted product. In this review, a comprehensive summary of the applications of DBD plasma in catalytic CO2 hydrogenation is provided in detail. Moreover, the state-of-the-art design of the reactor and optimization of reaction parameters are discussed. Furthermore, several mechanisms based on simulations and experiments are provided. In the end, the existing challenges of this hybrid system and corresponding solutions are proposed.

On the Effect of Cobalt Promotion over Ni/CeO2 Catalyst for CO2 Thermal and Plasma Assisted Methanation

In recent years, carbon dioxide hydrogenation leading to synthetic fuels and value-added molecules has been proposed as a promising technology for stabilizing anthropogenic greenhouse gas emissions. Methanation or Sabatier are possible reactions to valorize the CO2. In the present work, thermal CO2 methanation and non-thermal plasma (NTP)-assisted CO2 methanation was performed over 15Ni/CeO2 promoted with 1 and 5 wt% of cobalt. The promotion effect of cobalt is proven both for plasma and thermal reaction and can mostly be linked with the basic properties of the materials.