Benzotriazole (BTAH) has been used as a copper corrosion inhibitor since the 1950s. However, the molecular level detail of how adsorption and surface passivation occur remains a matter of debate. BTAH adsorption on a Cu(111) single crystal has been investigated from medium coverage to multilayer using scanning tunneling microscopy (STM), temperature-programmed desorption (TPD), high resolution electron energy loss (HREEL) spectroscopy and supporting density functional theory (DFT) calculations. Both physisorbed and chemisorbed phases are observed. One extended and highly ordered self-assembled metal−organic phase is seen at saturation coverage and above. A metastable phase is also observed. Complete desorption occurs at ca. 600 K. Those structures are critically discussed in the light of some of the various adsorption models reported in the literature and an alternative adsorption model is proposed. These results allow a further understanding of the interaction between benzotriazole and copper and, in turn, may help understanding the mechanism for protection of copper and copper alloys from corrosion, substantially contributing to a long-standing debate.

Benzotriazole (BTAH) has been used as a copper corrosion inhibitor since the 1950s; however, the molecular level detail of how inhibition occurs remains a matter of debate. The onset of BTAH adsorption on a Cu(111) single crystal was investigated via scanning tunnelling microscopy (STM), vibrational spectroscopy (RAIRS) and supporting DFT modelling. BTAH adsorbs as anionic (BTA(-)), CuBTA is a minority species, while Cu(BTA)2, the majority of the adsorbed species, form chains, whose sections appear to diffuse in a concerted manner. The copper surface appears to reconstruct in a (2 × 1) fashion.

Synthesis and structural characterization of the first LiFeO2 compound with tetrahedrally coordinated Fe3+ is reported. When used as a positive intercalation electrode in a lithium cell, it can store charge of up to 120 mAhg(-1) at a rate of 100 mAg(-1). However, it converts to the defect spinel LiFe5O8 on cycling. By combining results from powder X-ray diffraction, differential electrochemical mass spectrometry, electrochemical cycling, and TG-MS, it is shown that such conversion, which involved oxygen loss, is not associated with direct O2 gas evolution but instead reaction with the electrolyte. We suggest that intercalation/deintercalation is accompanied by the exchange of Li+ by H+ in the material and subsequent loss of H2O, thus converting LiFeO2 to the defect spinel LiFe5O8 on cycling.

Iminodiacetic acid (IMDA), NH(CH2CO2H)2, whose molecular structure is shown in figure 1, is a small molecule but has a very large scope for interacting with copper due to its two carboxylic acid and imine functionalities, which have been shown to bind strongly to copper [1,2,3]. The electronegative oxygen and nitrogen atoms present also make this a good candidate for hydrogen bonding, which often leads to very stable ordered two dimensional (2D) structures being formed across surfaces.