Boundary Layer of Photon Absorption Applied to Heterogeneous Photocatalytic Solar Flat Plate Reactor Design

Table 1

Heterogeneous photocatalysis reaction scheme based on semiconductor TiO₂, extracted from Turchi and Ollis [6].

Activation	TiO−−→2^ℎ𝜈𝑒^−+ℎ^+	(1)
Adsorption	O^2−Lattic+Ti^IV+H2O⇌OLH^−+Ti^IV−OH^−	(2a)
	Ti^IV+H2O⇌Ti^IV−H2O	(2b)
	Site+𝑅𝑖⇌𝑅𝑖,ads	(3)
	OH^•+Ti^IV⇌Ti^IV−OH^•	(4)
Recombination	𝑒^−+ℎ^+→heat	(5)
Hole trapping	Ti^IV−OH^−+ℎ^+⇌Ti^IV−OH^•	(6a)
	Ti^IV−H2O+ℎ^+⇌Ti^IV−OH^•+H^+	(6b)
	𝑅𝑖,ads+ℎ^+⇌𝑅^+𝑖,ads	(7)
Electron trapping	Ti^IV+𝑒^−⇌Ti^III	(8a)
	Ti^III+O2⇌Ti^IV−O2^•−	(8b)
Hydroxyl attack
Case I	Ti^IV−OH^•+𝑅𝑖,ads→Ti^IV+𝑅𝑗,ads	(9)
Case II	OH^•+𝑅𝑖,ads→𝑅𝑗,ads	(10)
Case III	Ti^IV−OH^•+𝑅𝑖→Ti^IV+𝑅𝑗	(11)
Case IV	OH^•+𝑅𝑖→𝑅𝑗	(12)