Sensitized triplet–triplet annihilation photon upconversion (sTTA-UC) allows blue-shifting non-coherent low-intensity light and is potentially useful in solar-powered devices, bioimaging, 3D printing, and other applications.

Single metal atoms confined in graphene have proven to be outstanding catalysts for various chemical reactions and promising candidates for gas sensing applications. However, it remains unclear whether their chemical activity is determined by the specific type of metal atom or is a direct consequence of the confinement itself.