Carbon‐based metal‐free catalysts for electrochemical CO2 reduction: Activity, selectivity, and stability

Zero or negative emissions of carbon dioxide(CO2)is the need of the times,as inexorable rising and alarming levels of CO2 in the atmosphere lead to global warming and severe climate change.The electrochemical CO2 reduction(eCO2R)to value‐added fuels and chemicals by using renewable electricity provides a cleaner and more sustainable route with economic benefits,in which the key is to develop clean and economical electrocatalysts.Carbon‐based catalyst materials possess desirable properties such as high offset potential for H2 evolution and chemical stability at the negative applied potential.Although it is still challenging to achieve highly efficient carbon‐based catalysts,considerable efforts have been devoted to overcoming the low selectivity,activity,and stability.Here,we summarize and discuss the recent progress in carbon‐based metal‐free catalysts including carbon nanotubes,carbon nanofibers,carbon nanoribbons,graphene,carbon nitride,and diamonds with an emphasis on their activity,product selectivity,and stability.In addition,the key challenges and future potential approaches for efficient eCO2R to low carbon‐based fuels are highlighted.For a good understanding of the whole history of the development of eCO2R,the CO2 reduction reactions,principles,and techniques including the role of electrolytes,electrochemical cell design and evaluation,product selectivity,and structural composition are also discussed.The metal/metal oxides decorated with carbon‐based electrocatalysts are also summarized.We aim to provide insights for further development of carbon‐based metal‐free electrocatalysts for CO2 reduction from the perspective of both fundamental understanding and technological applications in the future.

Development of Composite Textile Structures for Wound Dressing Applications

The main objective of this research work was the development of novel and responsive nonwoven composite structures containing gelling materials for wound management. The development of novel all inclusive collagen booster(CB) therapeutic nonwoven wound dressings was mainly focused on. It provides essential functional properties such as high absorption,vertical and lateral wicking,and antibacterial and acidic pH properties. The developed composite wound dressing consisted of carboxymethylcellulose(CMC) fibre and also it was reinforced with polylactic acid( PLA) fibre. The produced composite wound dressings were treated with two different CBs at 4% by using the spray method. The details of the CBs have not been disclosed in this paper due to the Intellectual Property Rights( IPR) issues. The important benefit of using CB treatment is that it allows the maintenance of an acidic pH environment at the wound area. It is well known that acidic pH reduces the wound healing time and enhances the wound healing process. Furthermore,one of the CBs not only promotes the proliferation of the epithelial cells in wounds but also can provide antibacterial action. The PLA fibre reinforced CMC composite dressing has enhanced wicking properties which help to minimise the pooling of exudate on the wound bed and as a result maceration is prevented. The CBs treated dressings maintain the wound bed in an acidic pH condition which also improves the wound healing process. In addition to the above-mentioned properties,the CB treatment imparts antimicrobial activity against Gram-positive and Gram-negative bacteria,thus resulting in the reduction in the propensity for wound infection. Ultimately,the research has proved that the 4% CB treatment enhances the antimicrobial activity and the acidic pH characteristics of the developed CMC /PLA composite wound dressings.

Fullerene(C_(60)) Nanowires: The Preparation,Characterization, and Potential Applications

Fullerene(C_(60))nanowires have attracted significant attention in the past two decades due to their outstanding chemical and physical properties,which render the material a wide range of potential applications.Much effort has been devoted to exploring the growth methods,structural and compositional characterizations,and application-related investigations of this novel carbon nanomaterial.Here,we present a review of C_(60)nanowires in which we will first describe the recent development in the material preparations,analytical techniques,crystal structures,chemical compositions,and the investigations of polymerization processes.Afterward,we will discuss the mechanistic studies on the nanowires’growth as the mechanism research is of great importance for their size control,large-scale preparation,and for the exploration of applications in a wide range of fields.Finally,we will discuss the potential applications in several directions,including optical,electrical,mechanical,and biological fields,as well as our perspectives to future developments.

Effective removal of Cd^2+ and Pb^2+ pollutants from wastewater by dielectrophoresis-assisted adsorption

Dielectrophoresis(DEP)was combined with adsorption(ADS)to simultaneously and effectively remove Cd^2+ and Pb^2+ species from aqueous solution.To implement the process,bentonite particles of submicro-meter size were used to first adsorb the heavy metal ions.These particles were subsequently trapped and removed by DEP.The effects of the adsorbent dosage,DEP cell voltage and the capture pool numbers on the removal rate were investigated in batch processes,which allowed us to determine the optimal experimental conditions.The high removal efficiency,97.3% and 99.9% for Cd^2+ and Pb^2+,respectively,were achieved when the ions are coexisting in the system.The microstructure of bentonite particles before and after ADS/DEP was examined by scanning electron microscopy.Our results suggest that the dielectrophoresis-assisted adsorption method has a high capability to remove the heavy metals from wastewater.