A scheme combining a scanning probe microscope with a quantum sensor can locally trigger water dissociation and observe the elementary steps of such a reaction.
Every experimental technique comes with trade-offs. High-resolution microscopy can pinpoint the positions of individual atoms, yet it typically cannot identify them chemically. Spectroscopy provides chemical information but often only as an averaged signal over a large region. To construct a comprehensive picture of processes at the nanoscale, researchers often resort to combining two or more independent methods. The metaphorical silver bullet would be a single technique that is both local and capable of identifying chemical species as they form and react. Now Wentian Zheng of Peking University and his collaborators have taken an impressive step toward that goal. They have combined two previously separate capabilities—quantum sensing and scanning probe microscopy (SPM)—into a single instrument that can trigger and observe chemical reactions with nanometer resolution [1].








