The modification of surfaces with self-assembled monolayers (SAMs) containing multiple different molecules, or containing molecules with multiple different functional components, or both, has become increasingly popular over the last two decades. This explosion of interest is primarily related to the ability to control the modification of interfaces with something approaching molecular level control and to the ability to characterise the molecular constructs by which the surface is modified. Over this time the level of sophistication of molecular constructs, and the level of knowledge related to how to fabricate molecular constructs on surfaces have advanced enormously. This critical review aims to guide researchers interested in modifying surfaces with a high degree of control to the use of organic layers. Highlighted are some of the issues to consider when working with SAMs, as well as some of the lessons learnt (169 references).

Organic functionalization of non-oxidized silicon surfaces, while allowing for robust chemical passivation of the inorganic substrate, is intended and expected to broaden the chemical, physical and electronic properties of the currently most relevant technological material. Numerous protocols are now available for the preparation of Si–C, Si–O and Si–N bound layers. In particular, the covalent attachment of 1-alkenes and 1-alkynes onto hydride-terminated Si(100) and Si(111) has seen a wealth of research activity starting from the pioneering work of Linford and Chidsey (Alkyl monolayers covalently bonded to silicon surfaces, J. Am. Chem. Soc., 1993, 115(26), 12631–12632). This critical review aims to bring together the available wet-chemical routes toward the formation of silicon–organic monolayers under ambient conditions. Particular emphasis is placed on discussing the reasons behind the need for novel chemical approaches that are straightforward, modular and of wide scope so as to allow the application of silicon electrodes in aqueous electrolytes. A general introduction to biomolecular recognition events at functionalized silicon surfaces is also presented (281 references).

Electrostatic catalysis, once considered theoretical daydreaming, is poised to enter mainstream chemistry, with viable platforms including single molecule experiments, electrified interfaces and pH-switchable charges.

The evolution of gaseous products is a feature common to several electrochemical processes, often resulting in bubbles adhering to the electrode’s surface. Adherent bubbles reduce the electrode active area, and are therefore generally treated as electrochemically inert entities. Here, we show that this general assumption does not hold for gas bubbles masking anodes operating in water. By means of imaging electrochemiluminescent systems, and by studying the anisotropy of polymer growth around bubbles, we demonstrate that gas cavities adhering to an electrode surface initiate the oxidation of water-soluble species more effectively than electrode areas free of bubbles. The corona of a bubble accumulates hydroxide anions, unbalanced by cations, a phenomenon which causes the oxidation of hydroxide ions to hydroxyl radicals to occur at potentials at least 0.7 V below redox tabled values. The downhill shift of the hydroxide oxidation at the corona of the bubble is likely to be a general mechanism involved in the initiation of heterogeneous electrochemical reactions in water, and could be harnessed in chemical synthesis.