Chemically Stable Sulfonated Polytriazoles Containing Trifluoromethyl and Phosphine Oxide Moieties for Proton Exchange Membranes

Fabrication of a High Proton-Conducting Sulfonated Fe-Metal Organic Framework-Polytriazole Composite Membranes: Study of Proton Exchange Membrane Properties

A series of hybrid composite membranes including polymer-metal-organic frameworks (MOFs), are synthesized using sulfonated Fe-MOF and sulfonated polytriazole (PTSF). After being post-modified by 1,3-propane sultone, the obtained Fe-S MOF is incorporated into the polytriazole polymer matrix through the solution blending method. Additionally, a series of polytriazole with a degree of sulfonation of 60 is prepared, with the percentage of the Fe-S MOF ranging from 3 to 9 weight percent. A comparison is made between the properties of these hybrid membranes and those of the pristine membranes. The hybrid membranes demonstrate a high degree of solubility in every solvent that is employed. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) confirm that the MOF is distributed uniformly throughout the polymer matrix. Moreover, well-separated morphologies are confirmed by transmission electron microscopy (TEM). The prepared hybrid membranes demonstrate enhanced proton conductivities, water absorption, and swelling, all of which are accomplished without influencing the oxidative stability values.

Live diatoms as potential biocatalyst in a microbial fuel cell for harvesting continuous diafuel, carotenoids and bioelectricity

Microbial fuel cell (MFC) with live diatoms (Nitzschia palea) displacing bacteria in the anodic chamber generated electrical potential. Unlike other microalgae, diatoms fix 25% of atmospheric CO2, thus releasing O2. They perform photolysis of water by photosynthesis in the plastid during light photoperiod and cellular respiration in the mitochondria during dark, producing electrons and protons, respectively. The electrogenic property of diatom was explored and evaluated by comparing the potential changes with reference fuel cell without diatoms and that operated with diatoms in the anodic chamber. Such photosynthetic diatom microbial fuel cell (PDMFC) employed f/2 media rich in nitrates, phosphates, metasilicates, trace metals and vitamins as the anolyte and potassium permanganate as catholyte enhanced the output voltage by 3rd day. The maximum power density for PDMFC was 12.62 mWm-2 and coulombic efficiency of 22.95%. Besides this, the fixed diatom cells at anode showed about 64.28% increase in lipid production on 15th day compared to that on 1st day along with the increment in formation of complex fatty acid methyl esters and carotenoids during its operation. Hence, diatoms can be envisaged to substitute bacteria in the anodic chamber of MFC to simultaneously produce bioelectricity and other valuable compounds. Further their silica nanoporous architecture serve as good absorbents for heavy metal removal found in many wastewaters.

High proton conductivity in a charge carrier-induced Ni(ii) metal–organic framework

A new tetradentate phosphonate ligand-based Ni-MOF has been synthesized and employed as an efficient proton-conducting material upon doping with sulphuric acid.

Review—Microbial Electrosynthesis: A Way Towards The Production of Electro-Commodities Through Carbon Sequestration with Microbes as Biocatalysts

There has been a considerable increment in the atmospheric CO2 concentration, which has majorly contributed to the problem of global warming. This issue can be extenuated by effectively developing microbial electrosynthesis (MES) for the sequestration of CO2 with the concurrent production of biochemical and biofuels. Though the MES technology is in its infancy, it has exhibited enormous potential for sustainable mitigation of CO2 and bioelectrosynthesis of multi-carbon organic compounds. The problem of storage of excess renewable electrical energy by conventional means can also be alleviated by employing MES, which stores it in the form of C–C bonds of chemicals. This review focuses on the various aspects of MES and recent developments made in this field to overcome its bottlenecks, such as the lower yield of organic compounds, separation of products of higher chain organic compounds, etc. In particular, the microbial catalysts and cathode materials employed in MES have also been emphasized. Keeping in mind the potential of this innovative technology, researchers should focus on improving the yield of MES by developing novel low-cost cathode materials and discovering efficient and robust micro-organisms, which would be a significant step forward towards the further advancement of this technology.