EES Blog

Scientists in China and Germany have carbonised corrugated cardboard and from it made layered corrugated carbon as a cheap, high performance electrode material for microbial fuel cells. The microbial bioelectrochemical system of the fuel cell works by using an anode to biocatalytically oxidise complex organic matter and convert this chemical energy into a current flow. With the cardboard, the cell reaches a current density of 40 mA cm^-2, one order of magnitude higher than current microbial bioelectrochemical systems, which achieve a current density of <4 mA cm^-2.

Read this hot EES communication in full today:

Layered corrugated electrode macrostructures boost microbial bioelectrocatalysis
Shuiliang Chen, Guanghua He, Qin Liu, Falk Harnisch, Yan Zhou, Yu Chen, Muddasir Hanif, Suqin Wang, Xinwen Peng, Haoqing Hou and Uwe Schröder
DOI: 10.1039/C2EE23344D

Professor Jeffrey R. Long and coworkers have evaluated a series of zeolites for their carbon capture properties using a new high-throughput gas adsorption instrument which can simultaneously measure 28 samples.

They identified one zeolite in particular which had superior CO₂ adsorption properties and CO₂/N₂ selectivity compared to Mg₂(dobdc) ((dobdc^4- = 1,4-dioxido-2,5-benzenedicarboxylate) – one of the best currently available adsorbent materials.

Read the full details of this HOT Energy & Environmental Science paper:

Evaluation of cation-exchanged zeolite adsorbents for post-combustion carbon dioxide capture
Tae-Hyun Bae, Matthew R. Hudson, Jarad A. Mason, Wendy L. Queen, Justin J. Dutton, Kenji Sumida, Ken J. Micklash, Steven S. Kaye, Craig M. Brown and Jeffrey R. Long
DOI: 10.1039/C2EE23337A

The first application of a cobalt(II)/(III) tris(2,2’-bipyridine)-based aqueous electrolyte in the fabrication of dye-sensitised solar cells has been carried out by scientists from Australia. In their Energy & Environmental Science paper, they report very high efficiency for an aqueous dye sensitised solar cell.

Cobalt(II)/(III) tris(2,2’-bipyridine)-based electrolytes have been used previously in liquid electrolytes using organic solvents. But, the disadvantages with these types of electrolytes are a high vapour pressure and they are not environmentally friendly.

Electrolytes based on ionic liquids, plastic crystals and solid state conductors have been explored but the ingress of moisture in these systems affects their stability.

Electrolytes based on water are attracting attention as water is cheap, abundant, non-toxic and non-flammable.

Read this exciting research article today:

Aqueous dye-sensitized solar cell electrolytes based on the cobalt(II)/(III) tris(bipyridine) redox couple
Leone Spiccia
DOI: 10.1039/C2EE23317G

A new recombination layer for use in tandem polymer solar cells has been developed by scientists in the US. Tandem polymer solar cells are two single-junction solar cells connected in series by a conducting layer (the recombination layer). The new layer – made of the conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) modified at one interface with ethoxylated polyethylenimine – results in the highest fill factor value (0.72) ever reported for a tandem polymer solar cell. The fill factor is the ratio of maximum obtainable power to the product of the open-circuit voltage and short-circuit current.

Read the full details of this exciting Energy & Environmental Science article today:

High performance polymeric charge recombination layer for organic tandem solar cells
Yinhua Zhou, Canek Fuentes-Hernandez, Jae Won Shim, Talha Mansur Khan and Bernard Kippelen
DOI: 10.1039/C2EE23294D

Enzyme-based biofuel cells have been plugged into lobsters and they generated enough power to run a digital watch. In a separate experiment, the same US scientists placed the biofuel cells in a fluidic system that mimicked human blood circulation and used them to power a heart pacemaker.

Biofuel cells coupled with enzymes can harvest electrical energy from biological fuels like glucose. This has led researchers to hope that they could one day power medical devices in people by burning fuel derived from the patient’s diet. Implanting these cells inside living organisms is still a challenge; however, researchers have managed to implant them in rats, rabbits, insects, snails and clams. Despite this work, no attempts have been made to use these enzymatic fuel cells to power real electronic devices as the voltages reached were not high enough (below 0.5V).

Two lobsters generate enough power to operate a watch. The biofuel cells filled with human serum power a pacemaker

Now, Evgeny Katz at Clarkson University, Potsdam, and colleagues, who did the work on the snails and clams, have implanted biofuel cells – connected in series – in two live lobsters. The enzyme-modified electrodes in the cells catalysed glucose oxidation and oxygen reduction in the fluid inside the lobster’s body, generating a current. The team found that the system could generate enough power to operate a watch (1.2V).

Read the article from EES:

From “Cyborg” Lobsters to a Pacemaker Powered by Implantable Biofuel Cells
Kevin MacVittie ,  Jan Halamek ,  Lenka Halámková ,  Mark Southcott ,  William D Jemison ,  Robert Lobel and Evgeny Katz
Energy Environ. Sci., 2012, Accepted Manuscript
DOI: 10.1039/C2EE23209J