High performance thylakoid bio-solar cell using laccase enzymatic biocathodes

Area of Science:

• Bio-electrochemistry
• Renewable energy conversion
• Photosynthesis-based devices

Background:

• Thylakoid membranes are known for electrochemical solar energy conversion.
• Previous designs suffered from low current output and open circuit voltage.
• Cathode limitations were identified as a key factor in reduced performance.

Purpose of the Study:

• To construct an improved bio-solar cell using thylakoid membranes.
• To enhance light-induced electrical power generation.
• To investigate the performance of a novel thylakoid bioanode and laccase biocathode system.

Main Methods:

• A two-compartment bio-solar cell was constructed with a thylakoid bioanode and laccase biocathode.
• Performance was compared to a cell using a platinum cathode.
• Electrode performance was evaluated in solutions of varying pH to assess a compartment-less design.

Main Results:

• The two-compartment cell demonstrated a >5-fold increase in short-circuit current density.
• An open-circuit voltage 0.275 V higher than the Pt-cathode cell was achieved.
• A membrane-less cell at pH 5.5 yielded a short-circuit photocurrent density of 14.0 ± 1.8 μA cm⁻², 25% higher than the two-compartment cell, with a similar open-circuit voltage.

Conclusions:

• The combination of thylakoid bioanode and laccase biocathode significantly improves bio-solar cell performance.
• A compartment-less design is feasible and offers enhanced photocurrent generation.
• This work presents a promising advancement in electrochemical solar energy conversion using biological components.