The University of Tokyo has discovered a way to waterproof paper using biodegradable materials that kill bacteria. It could help the global plastics crisis, they say. It's made of silica-resin-coated titanium dioxide nano-particles. When exposed to light, the coating can degrade pollutants like bacteria, rendering them non-biodegradable. The process can be used on cutlery and mulch. It's porous and absorbent, so it captures pollutants and photo-catalyzes them.