Quantum Tunneling Shows Promise for Solar Storage and Biosensing

Researchers at the University of Sydney have made use of quantum techniques for understanding the electrolysis of water, which is considered to be the application of an electric current to H₂O in order to produce the constituent elements oxygen and hydrogen.

They discovered that electrons can 'tunnel' through barriers in aqueous solutions away from the electrodes, neutralizing ions of impurities present in that water. It is possible to detect this in changes in current, which has applications for biosensing, referring to the detection of biological elements in solution.

This neutralization of ions in solution is a different concept to that presently believed, where the neutralization takes place only at the electrode surface.

In 1931, quantum tunneling in electrolysis was projected by Ronald Gurney (a student of Australian Nobel laureate William Bragg) but has not been yet been confirmed.

The idea that tunneling through water really does take place was suspected from current work on the scanning tunneling microscope, the invention which received the Nobel prize for physics in 1986.

This lays the basis for new and faster methods to detect biomedical impurities in water, with potentially important implications for biosensing techniques.

Professor David McKenzie, The School of Physics, The University of Sydney

Professor McKenzie also said, "A better understanding of electrolysis is becoming more important for applications in alternative energies in what is sometimes called the 'hydrogen economy'."

Solar energy only works when the sun is shining without storage methods.

In order to generate energy at other times, one method is to make use of electricity from solar cells to electrolyze water, generating hydrogen gas which can then be stored and also burned later to develop energy when required.

The tunneling effect refers to the quantum mechanical process in which a particle travels through a barrier that in classical physical theory should not happen.

Electrons can 'tunnel' in chemical and biological systems in a non-trivial manner that has allegations for photosynthesis and various other biological systems. It happens via barriers that are only a few nanometers thick, a billionth of a meter.