Construction of electrolytic cell:
The
evolution of hydrogen gas was carried out by the simple water splitting cell. First
work of our thesis is to construct the electrolysis cell device by using our
new technique i.e. by using our third electrode system. Generally, in this
system we have used third electrode (called grid electrode) in between the two
electrodes namely cathode electrode and anode electrode.
To
construct the cell device, at first, a spacer material is needed which should have the property of
chemical resistance, heat resistance, hard solidity, insulator and easy to
work. On the availability of spacer material in our local market we have used a
Polymer which have all properties required of a spacer material.
The simple voltammetry cell is shown in the Fig. 3.1.
The
cuboid shape of two polymer of dimension 10 cm×9.8 cm×1.8 cm is drilled into
square shape of dimension 5 cm×5 cm×1.8 cm. The drilled area is filled with
electrolyte solution (NaOH solution). Two holes are made diagonally at the
upper part of each polymer for insertion of plastic pipes of diameter 0.5 cm.
The holes are designed for the gas out. At the lower, side part of one polymer
is drilled to make a hole for the injection of electrolyte solution. Overall,
there are five holes of same diameter. The length of plastic pipes is fixed
such that the levels of electrolyte must be same level on all five pipes.
The inner upper
part of exposed area for electrolysis is attached diagonally by a small gas
separator of dimension 5 cm×3.5 cm. The effective area for the exchange of ions
during the electrolysis is 5 cm×5 cm. The area exposed part for electrolysis is
covered by the soft air tight material (wax).
Both side of each polymer cell is covered by the
gas trap cut by the same design of polymer cell to make the electrolyzer air
tight. The gas trap should also have the
property of chemical resistance, heat resistance, insulator and flexibility.
There are many materials available in the market which are used as a gas trap
but in our experiment we have used insole of the shoe of thickness nearly 1 mm. Keeping
the iron plate of dimension 6.5 cm×6.5 cm×0.1 cm as grid at the middle
of two polymer cell. The grid (plate) divides whole electrolytic space into two
equal parts where one mole solution of NaOH is stored. The outer part of the two polymer cell is now
closed by iron plate (cathode and anode electrode) of dimension 10.4 cm×9.7 cm×0.1 cm.
These plates are fixed by nuts and bolts using rigid wooden pieces. Wooden
pieces are used to prevent our electrolyzer from short circuit.
Electrolyte
is passed to cell through the pipe connected to the lower side hole of polymer
until the levels of electrolyte on all five pipes is maintained. Four pipes at
the upper roof of cell are used for the collection of gases, are connected to
burette. The burettes are kept inverted into water filled trough.
Fig. 1 Simple voltammetry
cell and Electrolyzer.
continue.........
