Microalgae derived activated biochar (ABC-900) was synthesized by thermal activation of biochar at 900 °C and the activated biochar was characterised to ascertain the applicability as low-cost electrocatalyst in microbial fuel cell (MFC). Characterisation of ABC-900 using energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy revealed presence of intrinsically doped nitrogen and phosphorus. Cyclic voltammetry exhibited that ABC-900 is an active electrocatalyst, which follows four electron pathway for oxygen reduction as estimated from Koutecky-Levich plot. Three MFCs, using electrocatalyst ABC-900 (MFC-ABC), Pt-C (MFC-Pt) and third MFC with bare carbon black coated cathode (MFC-CB), were operated for a period of 90 days using synthetic wastewater in batch mode (72 h) having chemical oxygen demand (COD) of 3 g L⁻¹ (carbon source: sucrose). Comparable COD removal efficiencies were observed in MFC-ABC (79.5 ± 5.1%) and MFC-Pt (79.0 ± 6.7%), while MFC-CB exhibited lower COD removal (73.5 ± 9.1%). Comparable maximum power density was achieved for MFC-ABC (12.86 ± 0.35 W m⁻³) and MFC-Pt (13.52 ± 0.05 W m⁻³) at much lower production cost for the former (0.3% cost compared to Pt-C). Thus, the present work established that microalgae derived activated biochar can act as a low-cost cathode catalyst for scaling-up applications of MFC.

通过在900°C下对生物炭进行热活化来合成微藻衍生的活化生物炭（ABC-900），并对活化生物炭进行表征，以确定其在微生物燃料电池（MFC）中作为低成本电催化剂的适用性。使用能量色散X射线光谱和X射线光电子能谱对ABC-900进行表征，发现存在固有掺杂的氮和磷。循环伏安法表明，ABC-900是一种活性电催化剂，根据Koutecky-Levich图估计，它遵循四个电子途径进行氧还原。使用批量生产的合成废水，使用电催化剂ABC-900（MFC-ABC），Pt-C（MFC-Pt）和带有裸碳黑涂层阴极的第三个MFC（MFC-CB）运行三台MFC，为期90天。模式（72 h）的化学需氧量（COD）为3 g L^-1（碳源：蔗糖）。在MFC-ABC（79.5±5.1％）和MFC-Pt（79.0±6.7％）中观察到了相当的COD去除效率，而MFC-CB的COD去除率较低（73.5±9.1％）。MFC-ABC（12.86±0.35 W m ^-3）和MFC-Pt（13.52±0.05 W m ^-3）达到了可比的最大功率密度，而前者的生产成本要低得多（与Pt-C相比成本为0.3％） 。因此，本工作确定了微藻衍生的活化的生物炭可以充当用于MFC的按比例放大应用的低成本阴极催化剂。