Visible light active photocatalyst from recycled disposable heating pads

Alpha-Fe₂O₃ (α-Fe₂O₃) is cheap and abundant and has potential to be a highly efficient photocatalyst for water splitting. According to the report, there are a huge amount of disposable heating pads being created every year, and the pads are used one time then thrown away. We found that the main product of used heating pads is α-Fe₂O₃. Here, we collect and purify the α-Fe₂O₃ powder in the used heating pads using low power consumption processes. It is shown that the recycled heating pads can be used as a cost-effective photocatalyst for H₂ energy and for decomposition of organic pollutants as well. Additionally, the plasmonic enhanced photocatalysis reaction of α-Fe₂O₃ is also investigated. It is found that H₂ evolution rate can be enhanced 15% using α-Fe₂O₃ nanoparticles coated with a thin Au layer. The degradation of methylene blue can also enhance 12% compared to photocatalyst α-Fe₂O₃ nanoparticles coated without Au layer.