Photocatalytic Water Splitting (TiO₂)

2H₂O → 2H₂ + O₂

Overview

Titanium dioxide absorbs UV light and generates electron-hole pairs that can split water into hydrogen and oxygen. Discovered by Fujishima and Honda in 1972, this reaction is the basis of artificial photosynthesis research. The bandgap of TiO₂ (3.2 eV) limits absorption to UV, so researchers are developing visible-light photocatalysts.

Participants

Role	Substance	Coefficient	State
Reactant	Water H₂O	2	(l)

Everyday Example

Self-cleaning glass windows are coated with TiO₂ that photocatalytically decomposes organic dirt when exposed to sunlight.

Industrial Importance

Photocatalytic water splitting could produce green hydrogen fuel from sunlight and water, a key goal of renewable energy research.

Properties

Type: Photochemical
Reversible: No
Energy: Endothermic
ΔH: 572.0 kJ/mol
Catalyst: TiO₂ (titanium dioxide)

Related Reactions

Chlorophyll Fluorescence Cis-Trans Isomerization of Retinal Dye-Sensitized Solar Cell (Grätzel Cell) Firefly Bioluminescence (Luciferin Oxidation) Luminol Chemiluminescence Ozone Decomposition by UV Ozone Formation by UV Light Photocatalytic NOx Removal Photochemical Cycloaddition ([2+2]) Photochemical Smog Formation (NO₂ Photolysis)

Frequently Asked Questions

What is the equation for Photocatalytic Water Splitting (TiO₂)?

The balanced equation is: 2H₂O → 2H₂ + O₂.

What type of reaction is Photocatalytic Water Splitting (TiO₂)?

Photocatalytic Water Splitting (TiO₂) is a photochemical reaction.

Is Photocatalytic Water Splitting (TiO₂) exothermic or endothermic?

Photocatalytic Water Splitting (TiO₂) is endothermic (absorbs energy). The enthalpy change (ΔH) is 572.0 kJ/mol.

What conditions are needed for Photocatalytic Water Splitting (TiO₂)?

This reaction requires a catalyst (TiO₂ (titanium dioxide)).