La historia de la química: Pequeña guía para navegantes. Parte I: Viejas y nuevas tendencias

Esta guía consta de dos partes. En la primera se describe el desarrollo de la historia de la química como área de investigación. Se analizan tanto los primeros trabajos de los químicos-historiadores de los siglos XVIII como las obras de los autores del siglo XIX como Hermann Kopp. También se estudia la incipiente institucionalización en las primeras décadas del siglo XX, con especial atención a las obras de Hélène Metzger y Aldo Mieli. Finalmente, se discuten las principales tendencias actuales. En un próximo artículo se ofrecerá una lista ordenada de recursos bibliográficos y electrónicos para trabajar en historia de la química.

Modification of Hematite Electronic Properties with Trimethyl Aluminum to Enhance the Efficiency of Photoelectrodes

The electronic properties of hematite were investigated by means of synchrotron radiation photoemission (SR-PES) and X-ray absorption spectroscopy (XAS). Hematite samples were exposed to trimethyl aluminum (TMA) pulses, a widely used Al-precursor for the atomic layer deposition (ALD) of Al2O3. SR-PES and XAS showed that the electronic properties of hematite were modified by the interaction with TMA. In particular, the hybridization of O 2p states with Fe 3d and Fe 4s4p changed upon TMA pulses due to electron inclusion as polarons. The change of hybridization correlates with an enhancement of the photocurrent density due to water oxidation for the hematite electrodes. Such an enhancement has been associated with an improvement in charge carrier transport. Our findings open new perspectives for the understanding and utilization of electrode modifications by very thin ALD films and show that the interactions between metal precursors and substrates seem to be important factors in defining their electronic and photoelectrocatalytic properties.