Metal organic frameworks (MOFs) as potential anode materials for improving power generation from algal biophotovoltaic (BPV) platforms

Abstract

Microalgae based biophotovoltaic (BPV) cells are substantiated as innovative renewable energy generation devices, owing to their ability in mimicking the catalytic activity of microorganisms for water splitting reaction along with an effectual reduction of carbon footprint in our environment. As the direct contact between algal cells and anodic surface effectually governs the electron transfer and overall BPV performance, the development of electrochemically active and stable catalysts is crucial for the evolution of high performance BPVs. Accordingly, the monoclinic structured copper (Cu) metal organic framework (MOF) is prepared through the simple ageing process and the consequent bimetallic (Cu-Nickel(Ni)) MOF is developed via the partial substitution of Cu2+ with Ni2+ nodes without any variation in the chemical structure of Cu-MOF. The as-formulated MOFs loaded indium tin oxides (ITOs) are exploited as BPV anodes and their influences on green energy generation by using the freshwater microalgae Chlorella sp. UMACC 313 as a catalytic system are scrutinized in detail. The electrochemical activeness and robust stability of as-fabricated BPV anodes are enunciated, respectively, from the cyclic voltammetry and chronoamperometry techniques. Cu-Ni MOF/ITO equipped BPV establishes the power density of 40 μWm−2, which is substantially higher than those of Cu-MOF/ITO and ITO. The substantial features of Cu-Ni MOF including the elevated structural integrity, existence of different metallic ions with the rational electrical conductivity, and supplemental functionality accelerate its maximum green energy generation performance. Thus, these verdicts establish a distinctive approach in tailoring the electrochemically active and stable MOF anode materials for the evolution of ecologically benevolent fuel cells.