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CB
hv
hv
H +
O 2
-
--
O -
H 2
Surface recombination
Bulk recombination
O 2
OH
+
+
+
H 2 O/OH -
H 2 O
VB
FIGURE 11.1
Schematic illustration of processes involved in semiconductor photocatalysis.
CB
CB
CB
E 0 (H + /H 2 )
E 0 (O 2 /H 2 O)
VB
VB
VB
(a)
(b)
FIGURE 11.5
Energy band bending strategies to narrow the band gap of semiconductor photocatalysts so as to match the
solar spectrum. (a) Element doping. (b) Solid solution.
Semiconductor
Metal
Semiconductor
CB
hv
hv
-
-
-
-
- -
-
-
Metal
+
+
+
+ + +
VB
(a)
(b)
FIGURE 11.9
Metal-semiconductor photocatalytic systems: (a) metal particle supported on semiconductor surface; (b) metal-
semiconductor core-shell structure.
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