Physics

Nanotechnology

Electrode

Organic chemistry

Nanoscopic scale

Hydrogen

Electrochromism

Dehydrogenation

Catalysis

Physical chemistry

Metal–insulator transition

Chemical physics

Ionic bonding

Chemistry

Metallurgy

Materials science

Insulator (electricity)

Metal

Miniaturization

Quantum mechanics

Optoelectronics

Biochemistry

Electric field

Nature Materials

Manipulating the insulator–metal transition in strongly correlated materials has attracted a broad range of research activity due to its promising applications in, for example, memories, electrochromic windows and optical modulators1,2. Electric-field-controlled hydrogenation using ionic liquids3–6 and solid electrolytes7–9 is a useful strategy to obtain the insulator–metal transition with corresponding electron filling, but faces technical challenges for miniaturization due to the complicated device architecture. Here we demonstrate reversible electric-field control of nanoscale hydrogenation into VO2 with a tunable insulator–metal transition using a scanning probe. The Pt-coated probe serves as an efficient catalyst to split hydrogen molecules, while the positive-biased voltage accelerates hydrogen ions between the tip and sample surface to facilitate their incorporation, leading to non-volatile transformation from insulating VO2 into conducting HxVO2. Remarkably, a negative-biased voltage triggers dehydrogenation to restore the insulating VO2. This work demonstrates a local and reversible electric-field-controlled insulator–metal transition through hydrogen evolution and presents a versatile pathway to exploit multiple functional devices at the nanoscale. The authors realize local and reversible hydrogenation of VO2 using a Pt-coated scanning probe microscope tip and forming gas.

Manipulating the insulator–metal transition through tip-induced hydrogenation