We selected Goal 14, ""Life Below Water,"" from the United Nations Sustainable Development Goals (SDGs), which is closely related to Taiwan, as the focus of our research. To address pollution caused by crude oil spills, we incorporated photocatalytic technology—introduced in our textbooks—and independently developed nano-sized titanium dioxide–sodium alginate beads (hereafter referred to as TiO₂–alginate beads). These beads were integrated with microbial fuel cell (MFC) technology in an attempt to tackle the issue effectively. In this experiment, we chose biodegradable sodium alginate gel as a photocatalyst support material, replacing the plastic sponge commonly used in previous studies. This modification ensures that the photocatalytic component of the system poses no environmental harm. During the degradation process, the photocatalytic properties of TiO₂ are first employed to efficiently break down high-molecular-weight organic pollutants into low-molecular-weight compounds. These intermediate products are then further degraded by the MFC into harmless metabolic byproducts. Compared with current treatment methods, our approach is more environmentally friendly and generates energy during the process, thereby achieving the goal of sustainability.