An ecological self-purification pathway: Natural lava-Rhodopseudomonas palustris synergy enables spontaneous photobioelectrocatalysis for efficient dye degradation

Persistent synthetic dyes such as crystal violet pose substantial challenges to environmental remediation due to their high structural stability and toxicity. Here, we report a natural photobioelectrocatalytic strategy for dye removal by coupling the photosynthetic bacterium Rhodopseudomonas palustris K7 with natural volcanic lava. Characterization results demonstrated that the lava is an N-type semiconductor with a band gap of 3.32 eV and a flat-band potential of −0.87 V, enabling photoinduced