The indiscriminate use of fossil fuels has led to several challenges such as greenhouse gas emissions, environmental degradation, and energy security. Establishment of clean fuels is at the forefront of science and innovation in today's society to curb these problems. Dark fermentation (DF) is widely regarded as the most promising clean energy technology of the 21st century due to its desirable properties such as high energy content, its non-polluting features, its ability to use a broad spectrum of feedstocks and inoculum sources, as well as its ability to use mild fermentation conditions. In developing nations, this technology could be instrumental in establishing effective waste disposal systems while boosting the production of clean fuels. However, DF is still hindered by the low yields which stagnate its commercialization. This paper reviews the recent and emerging technologies that are gaining prominence in DF based on information that has been gathered from recent scientific publications. Herein, novel enhancement methods such as cell immobilization, nanotechnology, mathematical optimization tools, and technologies for biogas upgrading using renewable H 2 are comprehensively discussed. Furthermore, a section which discusses the potential of bioenergy in Sub-Saharan Africa including South Africa is included. Finally, scientific areas that need further research and development in DF process are also presented.

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The electrodeposition of platinum from hexachloroplatinic acid solutions, on glassy carbon, was studied by developing multiple cyclic voltammetry transients. The development of an isopotential point, only observed under hydrogenevolution conditions, is postulated to be associated with the reduction of [PtCl 4 ] 2− to Pt 0 and the oxidation of the adsorbed molecular hydrogen ion (H 2 + ) ads species to (H 3 O + ) ads . The adsorption of H 2 + inhibits the continued reduction of [PtCl 4 ] 2− and the 'cleansing' of the platinum surface, that is, the removal of H 2 + through hydrogen evolution, results in the opening up of active sites to allow for the continued reduction of [PtCl 4 ] 2− on the return sweep, which results in an isopotential point (IPP). This IPP is not observed in the absence of hydrogen evolution, due to saturation of the surface by (H 2 + ) ads , and correlates with a model that explains the interplay between platinum chloride species, hydrogen containing species (H 2 O/H 3 O + /H 2 + ), and the hydrogenevolution reaction.