TECTONIC HYDROGEN AND TECTONIC OXYGEN PRODUCTION THROUGH DEFORMATION OF PIEZOELECTRIC MINERALS IN PRESENCE OF WATER

A high concentration of hydrogen is used to characterize the gases occur in fracture zone of active faults, and it has been reported early to be associated with historical earthquakes. We propose a mechanism, a Piezoelectrochemical (PZEC) Effect for the direct conversion of mechanical energy to chemical energy explaining the phenomenon described. This effect is applied for generating hydrogen and oxygen via direct-water decomposition by means of naturally formed piezoelectric crystals including quartz, serpentine, kaolinite, and dickite. Laboratory experiments showed H₂ gas is generated from strained piezoelectric material due to its extreme low solubility, suggesting that the deformed or strained mineral surfaces can catalyze water decomposition (Hong et al., 2010, 2012). If the strain-induced H₂ production is significant, hydrogen measurements at monitoring sites offer information at depth on deformation of rocks that operates prior to earthquakes. The tectonic hydrogen could be a potential energy source to deep subsurface microbial communities that rely on molecular hydrogen for metabolism. Oxygen can be measured in water due to its high solubility. Our experimental results demonstrated that the dissolved oxygen generated from PZEC effect can oxidize dissolved dye and aqueous ferrous iron in form of Fe(II)-silicate metal complex. The hydrogen and oxygen formed through stoichiometry decomposition of water in presence of strained or deformed minerals in fault zones (including subduction zones and transform faults) may be referred as tectonic hydrogen and tectonic oxygen, respectively. The tectonic oxygen could be an important oxidizing agent dissolved in water during early earth time period, when early earth’s oxygen level was extremely low. Reported "whiffs" of dissolved oxygen before Great Oxidation Event (GOE) might be related to tectonic activities.

Hong, K-S, Xu, H., Konishi, H., and Li, X. (2010) Direct water splitting through vibrating piezoelectric micro-fibers in water. Journal of Physical Chemistry Letters, 1, 997-1002.

Hong, K.-S., Xu, H., Konishi, H., and Li, X. (2012) Piezoelectrochemical effect: A new mechanism for Azo dyes decolorization in aqueous solution through vibrating piezoelectric micro-fibers. Journal of Physical Chemistry C, 116, 13045-13051.