Conductive carbon nanotube hydrogel as a bioanode for enhanced microbial electrocatalysis

Enhancing microbial electrocatalysis through new material design is essential to the efficient and stable operation of bio-electrochemical system (BES). In this work, a novel conductive carbon nanotube (CNT) hydrogel was fabricated by electrodepositing both CNT and chitosan onto a carbon paper electrode and used as a BES anode electrode. The microscopic, spectroscopic, and electrochemical analytical results show that the CNT hydrogel exhibited an excellent electrochemical activity. In the BES tests, the current generation and the maximum power density of the MFC with the CNT hydrogel increased by 23% and 65%, respectively, compared with the control. This demonstrates that the utilization of such a hydrogel offers an effective approach to enhance the current generation of BES. The great conductivity of CNT and the high content of oxygen-containing functional groups (C-OH, C═O, etc.) on their surface were found to be responsible for the improvements. Our work provides a facile way to prepare appropriate BES electrodes and offers a straightforward and effective route to enhance the BES performance.