EN 16981:2021

SLOVENSKI STANDARD
01-december-2021
Nadomešča:
SIST-TS CEN/TS 16981:2017
Fotokataliza - Slovar izrazov
Photocatalysis - Glossary of terms
Photokatalyse - Glossar der Begriffe
Photocatalyse - Glossaire de termes
Ta slovenski standard je istoveten z: EN 16981:2021
ICS:
01.040.25 Izdelavna tehnika (Slovarji) Manufacturing engineering
(Vocabularies)
25.220.01 Površinska obdelava in Surface treatment and
prevleke na splošno coating in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 16981
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2021
EUROPÄISCHE NORM
ICS 01.040.25; 25.220.01 Supersedes CEN/TS 16981:2016
English Version
Photocatalysis - Glossary of terms
Photocatalyse - Glossaire de termes Photokatalyse - Glossar der Begriffe
This European Standard was approved by CEN on 18 July 2021.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 16981:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 7
1 Scope . 8
2 Normative references and notes . 8
3 Terms and definitions . 8
Bibliography . 55

European foreword
This document (EN 16981:2021) has been prepared by Technical Committee CEN/TC 386
“Photocatalysis”, under WG 1 “Terminology”, the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by April 2022, and conflicting national standards shall be
withdrawn at the latest by April 2022.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes CEN/TS 16981:2016.
In comparison with the previous edition, the following technical modifications have been made:
— Change of the Scope: “The glossary lists a consistent set of definitions to be used in standards on
photocatalysis for their consistency and connection with the scientific literature”.
— Change to Clause 2: Paragraphs were updated:
"Normative references and notes
There are no normative references in this document.
Most of the definitions reported in this document are a sub-set of the IUPAC definitions in
photocatalysis and radiocatalysis [1]. Some other definitions, in particular for the photocatalytic
rate and reactors, are taken from a dedicated work [2].
The technical specifications for the apparatus and physical values for irradiation conditions to be
used in the standards are reported in a separate Technical Specification [3].
For the magnitudes implying energy or photons incident on a surface from all directions, the set of
symbols recommended by the International Organization for Standardization (ISO) [4] and
included in the IUPAC “Green Book”, and by the International Commission on Illumination [5] are
adopted. This has been done primarily to comply with internationally agreed-upon symbols.”
— Clause 3: introductory wording and definitions were updated:
“ISO and IEC maintain a generic terminological databases for use in standardization, which could
complement this dedicated Glossary, at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
The arrangement of entries is alphabetical, and the criterion adopted by the IUPAC has been
followed for the typeface used: italicized words in a definition or following it indicate a cross-
reference in the Glossary.
SI units are adopted, with some exceptions, prominently in the use of the molar decadic absorption
coefficient, ε, with common units dm3 mol–1 cm–1 and a mole of photons denoted as an einstein.
As recently the definition of the SI units was established in terms of a set of seven defining
constants, including the Avogadro number, the mole (symbol: mol) is the base unit of amount
(number) of substance.
Functional dependence of a physical quantity f on a variable x is indicated by placing the variable in
parentheses following the symbol for the function; e.g. ε(λ). Differentiation of a physical quantity f
with respect to a variable x is indicated by a subscript x; e.g. the typical spectral radiant power
quantity Pλ = dP/dλ. The natural logarithm is indicated with ln, and the logarithm to base 10 with
log.”
The following definitions were deleted:
— amalgam lamp (before 3.17),
— back electron-transfer (before 3.20)
— bioluminescence (before 3.25),
— charge-transfer (CT) absorption (before 3.35),
— charge-transfer (CT) complex (before 3.36),
— charge-transfer (CT) state (before 3.37),
— circular dichroism (CD) (before 3.43)
— charge hopping(before 3.31),
— circular dichroism (CD) (before 3.43),
— current yield see photocurrent yield(before 3.49),
— dielectric (before 3.59),
— differential quantum (before 3.60),
— diode light emitting (LED) (before 3.61),
— driving force (before 3.63),
— driving force (for electron transfer) (before 3.64),
— electron-transfer photosensitization (before 3.69),
— emissivity see emittance(before 3.73),
— excitation transfer see energy transfer (before 3.77),
— flash photolysis(before 3.85),
— FWHM(before 3.95),
— germicidal lamp(before 3.97),
— hypsochromic shift(before 3.103),
— inner-filter effect(before 3.106),
— inner-sphere electron transfer(before 3.107),
— interferometer(before 3.113),
— Lambert–Beer law (before 3.116),
— Lambert law (before 3.117),
— LED(before 3.119),
— light-emitting diode (LED) (before 3.121),
— low-pressure mercury lamp (arc) (before 3.123),
— medium-pressure mercury lamp (arc) (before 3.127),
— mercury–xenon lamp (arc) (before 3.129),
— multiphoton process(before 3.132),
— OLED (before 3.135),
— OPA (before 3.137),
— OPO (before 3.138),
— optical multichannel analyzer (OMA) (before 3.140),
— optical parametric amplification process (before 3.141),
— optical parametric oscillator (OPO) (before 3.142),
— optoacoustic spectroscopy(before 3.143),
— photo-assisted catalysis(before 3.148),
— photohydration(before 3.166),
— photon emittance(before 3.174),
— photopolymerization(before 3.185),
— quartz–iodine lamp(before 3.194),
— radiant energy fluence rate(before 3.201),
— reactor CSTR(before 3.210),
— reflection factor (before 3.214),
— reflectivity(before 3.215),
— self-absorption (before 3.219),
— self-quenching (before 3.220),
— sensitizer (before 3.221),
— sensitization (before 3.222),
— singlet oxygen (before 3.223),
— singlet state(before 3.224),
— solvent shift(before 3.226),
— spectral radiant energy, Qλ(before 3.238),
— spectral sensitization(before 3.244),
— tungsten-halogen lamp(before 3.248),
— wolfram lamp(before 3.259),
The following definitions were updated:
— 3.11 actinic.
— 3.12 actinism.
— 3.18 attenuance filter
— 3.28 Brewster angle
— 3.64 extinction coefficient
— 3.65 Fermi level
— 3.71 fluorescence spectrum
— 3.92 Fourier-transform spectrometer
— 3.93 Fourier-transform spectroscopy
— 3.95 mercury lamp
— 3.100 organic light-emitting device
— 3.102 phosphorescence
— 3.103 photoacoustic spectroscopy
— 3.113 photocuring
— 3.116 photodynamic effect
— 3.140 photoreaction
— 3.142 photosensitization
— 3.143 photosensitizer
— 3.145 quantum efficiency
— 3.152 radiant energy fluence
— 3.158 rate of photon absorption
— 3.159 reaction rate
— 3.160 reactor batch
— 3.163 red shift
— 3.165 RGB color model
— 3.191 UV dose
The following definitions were added:
— 3.137 photonic unit conversion
— 3.161 reactor continuous Stirred-Tank
— 3.162 reactor plug flow
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Introduction
Photocatalysis is a very efficient advanced oxidation technique which enables the production of active
species following light absorption by the photocatalyst, such as bound/free hydroxyl radicals (∙OH),
hydroperoxyl radicals (∙OOH) and other ROS, conduction band electrons and valence band holes,
capable of partly or completely mineralising/oxidising the majority of organic compounds. The most
commonly used photocatalyst is titanium dioxide (TiO ). Photocatalysts can be used in powder form or
deposited as thin films on different substrates (glass fibre, fabrics, plates/sheets, etc.). The objective of
standardization is to introduce test standards for evaluation of the performance of photocatalysts
(including photocatalysis and photo-induced effects). These standards mainly concern tests and
analysis methods, and require a common language.
A common language for standards, disclosed to a wide audience and referring only to the operational
protocols and to their outcomes, is needed for a consistent set of standards and the connection with the
scientific literature. This glossary will take into account existing glossary of terms and literature
definitions used in photocatalysis and photochemistry. Because in photocatalysis numerous properties
are difficult to be evaluated, in this Glossary and in related standard norms the report of properties
depending on some physical-chemical properties and model parameters, like the number of active sites,
the mechanisms of adsorption or kinetic mechanisms of photocatalytic reactions is avoided.
Safety statement
Persons using this document should be familiar with the normal laboratory practice, if applicable. This
document does not address safety problems, if any, associated with its use. It is the responsibility of the
user to establish appropriate safety and health practices and to ensure compliance with any regulatory
conditions.
Environmental statement
It is understood that some of the material described in this document may have negative environmental
impact. As technological advantages lead to better alternatives for these materials, they will be
eliminated from this document to the possible extent.
At the end of the test, the user of this document will take care to carry out an appropriate disposal of the
wastes, according to local regulation.
1 Scope
The glossary lists a consistent set of definitions to be used in standards on photocatalysis for their
consistency and connection with the scientific literature.
2 Normative references and notes
There are no normative references in this document.
Most of the definitions reported in this document are a sub-set of the IUPAC definitions in
photocatalysis and radiocatalysis [1]. Some other definitions, in particular for the photocatalytic rate
and reactors, are taken from a dedicated work [2].
The technical specifications for the apparatus and physical values for irradiation conditions to be used
in the standards are reported in a separate Technical Specification [3].
For the magnitudes implying energy or photons incident on a surface from all directions, the set of
symbols recommended by the International Organization for Standardization (ISO) [4] and included in
the IUPAC “Green Book”, and by the International Commission on Illumination [5] are adopted. This has
been done primarily to comply with internationally agreed-upon symbols.
3 Terms and definitions
For the purposes of this document, the fo
...