Bifunctional Polyoxometalate-Carbon Foam Composite: Photocatalytic Degradation of Organic Pollutants and Synergistic Photosynthesis of High-Value-Added Chemical Fuels

Polyoxometalates (POMs) have attracted much attention in photocatalytic degradation of organic pollutants due to their environmental friendliness, high catalytic activity, and abundant redox sites from their unique structures. However, their practical use in liquid–solid photocatalytic systems is restricted by issues like low specific surface area, agglomeration tendency, and high water solubility. To address these problems, we used polyurethane foam (a common solid waste) as a template and phenolic resin as a carbon source to synthesize a highly porous carbon foam. POMs were anchored and dispersed on it via the sol–gel method. Techniques such as FTIR, XRD, XPS, Raman spectroscopy, and TEM confirmed the successful immobilization. The resulting composite showed excellent photocatalytic performance, with degradation rates over 90% for pollutants like methylene blue, rhodamine B, and methyl orange. It also had good stability, maintaining its structure after 1000 min of continuous operation. Moreover, the post-reaction solution was tested for photocatalysis. Analyses showed that the catalyst converted carbonate species in water into valuable fuels like CO and CH4, enabling both pollutant degradation and production of high-value-added products in a clean and sustainable way.