7th Korea-US Nanoforum
Nanostructured Materials for Light
Conversion and Energy Storage
Hyunwoong Park
School of Physics and Energy Science
Kyungpook National University
Solar-Powered Urban Metabolism
Major Hydrogen Production Processes
CH 4 + H 2O → CO + 3H 2
CO + H 2O → CO2 + H 2
95% in the U.S.
48% in the world
Huge Carbon Footprint
CO2/H2 (wt) = 2.5
25
Incomplete Reaction
→ CO generation
ti
Source: www.hydrogenassociation.org/general/factSheets.asp
Key Findings from the Commercial
Electrolysis
54-67 kWh/kg-H2
39 kWh/kg-H2
Electricity cost is a major component of H2 cost
Source: Summary of Electrolytic Hydrogen Production, NREL 2004
Solar Light-Driven Electrolysis with Water
Treatment
PV
M
Fuel Cell
Hydrogen
Storage
P
Wastewater
Cathode
CO2
Anode
H 2O
H2
H2
Treated water
O2 or Air
12:40
13:30
14:20
15:10
1150
-2
11:50
1100
10
4.4
1050
1.0
4.2
0.8
0.6
0
6
30
03
0.3
20
0.2
10
0.1
0.0
50
100
150
Time (min)
200
250
0
300
1.2
09
0.9
0.6
Ct/C0
Phenol
0
ICell (A)
15
4.0
4
0
0.4
[H2 ] (m
mmol/min
n)
11:00
ΙS (W m )
10:10
20
[CO2 ] ((μmol/min
n)
ECell (V)
Temp (C)
PV-Electrochemical Hybrid
0.3
0.0
April 18, 2007, Sunny
Acknowledgements
K-CAP
National Research Foundation
Dr. Soonhyun Kim at DGIST
Photoenergy Conversion (PECL) group members
2nd-year grads
TiO2 nanofiber
ZnO nanorod
1st-year grads
TNT-Fe2O3
CNT-H2
M-Fe2O3
Electrocatalysts
WO3