Cover in ChemSusChem:
Ever wonder what you can do with the flushed wastewater other than channeling it to sewage treatment plant? Assoc Prof Wey Yang Teoh and his team reported the direct generation of solar electricity from wastewater using a PhotoFuelCell constructed from specially designed nanostructured photoelectrodes.
Under solar irradiation, the nanostructured photoelectrode generates electron-hole pairs. Under normal circumstances, these charge carriers recombine within nanoseconds, and hence very little energy can be extracted. Here, the Assoc Prof Teoh and his team showed that the presence of organic wastes in the wastewater increases the efficiency of the electric production by almost 10 folds! In the process, the organics content removed and hence the wastewater is being cleaned. The effort is being highlighted as the cover of ChemSusChem, and the lead author of the paper is Dr Chenyan Hu, a former PhD student of Assoc Prof TeohThe team of Assoc Prof Teoh is now collaborating with the Drainage Services Department to design an even higher efficiency device to harness electricity out of the different domestic wastewater sources in Hong Kong.
Cover in CrystEngComm:
The teams of Assoc Prof Wey Yang Teoh at City University of Hong Kong, Prof Atsushi Urakawa of ICIQ Spain, and Prof Lutz Maedler at the University of Bremen reported the synthesis of delta-Bi2O3 with extremely low amount of dopants.
Delta-Bi2O3 is known to be one of the most efficient oxygen ion conductors around. It is a holy grail electrolyte material that potentially paves the way for the construction of highly-efficient low-temperature solid oxide fuel cells (SOFCs). The current SOFC technology requires operation at high temperatures at above 800 deg C, just so that sufficient oxygen ion conductivities can be achieved using the standard yttria-stabilized zirconia electrolyte. Unfortunately, the high temperature operation inevitably lowers the chemical-to-electricity conversion efficiencies in fuel cells. The replacement with delta-Bi2O3 potentially reduces the SOFC operating temperature to below 300 deg C, provided that the metastable material is not overly doped that it becomes weakly conductive.
Here, the collaboration of Profs Teoh, Urakawa and Maedler and their teams capitalised on the combined high temperature and rapid quenching processes in the flame spray pyrolysis to produce delta-Bi2O3 nanoparticles with only 2.5% Mn and 2.5% Ti dopants. This is by far the lowest amount of dopants ever been reported. The work appeared as the Front Cover of CrystEngComm (RSC Publishing), and was selected as the Hot Article in 2016. The lead author of the paper is Dr Jochen A.H. Dreyer, the inaugural Hong Kong PhD Fellowship recipient of the School of Energy and Environment. Dr Dreyer is now pursuing his research career at the University of Cambridge.