NOVELTY - Metal-containing nanofibers and/or nanotubes are produced by mixing metal-containing precursor mixture containing greater than or equal to 1 metal-containing pre-cursors, polymer mixture containing greater than or equal to 1 polymers and solvent to obtain 1st mixture, electrospinning 1st mixture to obtain polymer/metal-containing precursor nanofibers, heating polymer/metal-containing precursor nanofibers at 300-1500 degrees C in heating process, and monitoring heating process by measuring multiple transmission electron microscopy (TEM) images of polymer/metal-containing precursor nanofibers during heating process.    USE - Production of metal-containing nanofibers and/or nanotubes as catalyst, catalyst in water electrolysis, material in solid oxide fuel cells (SOFC), material in regenerative fuel cells, material in lithium air batteries, material in thermal-electrical device, material in magnetic cooling device, material in flue gas purification devices, material in oxygen membrane, material in liquid/gas filtrations, material in gas storage device or material in electrochemical pseudo capacitors (all claimed).    ADVANTAGE - Morphology of nanofibers and/or nanotubes is followed in real time by transmission electron microscopy (TEM) measurements.    DETAILED DESCRIPTION - Metal-containing nanofibers and/or nanotubes are produced by mixing metal-containing pre-cursor mixture containing greater than or equal to 1 metal-containing pre-cursors, polymer mixture containing greater than or equal to 1 polymers and solvent to obtain 1st mixture, electrospinning 1st mixture to obtain polymer/metal-containing precursor nanofibers, heating polymer/metal-containing precursor nanofibers at 300-1500 degrees C in heating process, and monitoring heating process by measuring multiple transmission electron microscopy (TEM) images of polymer/metal-containing precursor nanofibers during heating process as transformed into metal-containing nanofibers and/or nanotubes in which morphology of metal-containing nanofibers and/or nanotubes is controlled by monitoring of heating process. An INDEPENDENT CLAIM is included for a use of metal-containing nanofiber and/or nanotubes as catalyst, catalyst in water electrolysis, material in solid oxide fuel cells (SOFC), material in regenerative fuel cells, material in lithium air batteries, material in thermal-electrical device, material in magnetic cooling device, material in flue gas purification devices, material in oxygen membrane, material in liquid/gas filtrations, material in gas storage device or material in electrochemical pseudo capacitors.