DOI: 10.5281/zenodo.17338324
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Ma e ials Science: Ad ances in Syn hesis, Cha ac e iza ion and Applica ions (Vol. 1) - Digamba M. Sapkal, Ha shal M.
Bachha , Gau a Mahade Loha , Sanjay P. Khai na (Eds.)
ISBN: 978-93-95369-55-8 (pape back) 978-93-95369-46-6 (elec onic) | © 2025 Ad en Publishing.
h ps://doi.o g/10.5281/zenodo.17338324
CHAPTER 15
In luence o Mn Doping on he C ys allini y and
Mo phology o Ce ium Oxide Nanopa icles Syn hesized
by Co-p ecipi a ion
Nandkisho S. Sangle,a* Sangi a S. Mesh amb*
a,bPhysics Depa men , VPM’S B. N. Bandodka College o Science (Au onomous), Building 6,
Jnanadweepa, Chendani Bunde Road, Thane Wes , Thane 400601 Maha ash a, India
Co esponding au ho Email: nssangle@ pm hane.o g,a ssmesh am@ pm hane.o gb
Recei ed: 25 Augus 2025; Accep ed: 13 Oc obe 2025; A ailable online: 13 Oc obe 2025
Abs ac : In his s udy, we epo he syn hesis and cha ac e iza ion o pu e ce ium oxide (CeO₂) and
manganese-doped ce ium oxide (Mn–CeO₂) nanopa icles using he co-p ecipi a ion me hod. This
syn hesis ou e o e s a simple and e icien pa hway o ob aining high-pu i y nanoma e ials. S uc u al
and op ical p ope ies o he syn hesized nanopa icles we e analysed using X- ay di ac ion (XRD), ield
emission scanning elec on mic oscopy (FESEM), and UV- isible di use e lec ance spec oscopy (UV-
DRS). XRD analysis con i med he o ma ion o c ys alline CeO₂ wi h a luo i e cubic s uc u e, bo h in
pu e and Mn-doped samples. The inco po a ion o Mn did no al e he p ima y c ys al phase bu may
ha e induced sub le la ice dis o ions. FESEM images e ealed ha he pa icle size anges om
Nandkisho S. Sangle, Sangi a S. Mesh am
Ma e ials Science: Ad ances in Syn hesis, Cha ac e iza ion and Applica ions (Vol. 1) - Digamba M. Sapkal,
Ha shal M. Bachha , Gau a Mahade Loha , Sanjay P. Khai na (Eds.)
ISBN: 978-93-95369-55-8 (pape back) 978-93-95369-46-6 (elec onic) | © 2025 Ad en Publishing.
212
app oxima ely 10 nm o 40 nm, indica ing success ul nanoscale syn hesis. UV-DRS esul s demons a ed
enhanced isible ligh abso p ion in Mn-doped CeO₂ compa ed o pu e CeO₂, sugges ing a na owed
bandgap and po en ial o imp o ed pho oca aly ic pe o mance. These indings highligh he in luence o
Mn doping on he s uc u al and op ical beha iou o ce ium oxide nanopa icles.
Keywo ds: Ce ium Oxide Nanopa icles, Mn-Doped CeO₂, Co-P ecipi a ion Me hod, S uc u al
Cha ac e iza ion, Op ical P ope ies, XRD, UV-DRS, FESEM
1. In oduc ion
Ce ium is a a e ea h elemen and he second membe o he lan hanide se ies in he pe iodic able. A
de ining ea u e o a e ea h elemen s is he shielding o hei 4 o bi als by ou e 5p and 4d elec ons,
which impa s unique elec onic and ca aly ic p ope ies.1 Unlike mos lan hanides, ce ium can exis in
bo h +3 and +4 oxida ion s a es,2 enabling edox lexibili y ha is cen al o i s ca aly ic unc ionali y.
In bulk o m, ce ium oxide p ima ily exis s as CeO₂ (ce ium(IV) oxide) and Ce₂O₃ (ce ium(III)
oxide). Howe e , a he nanoscale, ce ium oxide nanopa icles (CeO₂ NPs) o en con ain a mix u e o Ce³⁺
and Ce⁴⁺ ions, pa icula ly on he su ace, due o oxygen acancies and su ace de ec s. This mixed
alence s a e is c ucial o many o he ma e ial’s excep ional p ope ies. Ce ium oxide nanopa icles ha e
been widely in es iga ed o a ange o echnological and biomedical applica ions. These include solid
oxide uel cells,3 high- empe a u e oxida ion- esis an coa ings,4 ca aly ic sys ems5,6 sola ene gy de ices7
and po en ial pha maceu ical agen s.8 Among hese, hei mos p ominen applica ion lies in ca alysis,
whe e hei edox beha io and oxygen s o age capaci y (OSC) make hem ideal ma e ials. CeO₂ and
CeO₂-based composi es ha e gained signi ican a en ion as ca alys s and as s uc u al and elec onic
p omo e s in he e ogeneous ca aly ic eac ions.5 Indus ially, ce ium oxide is ex ensi ely used in h ee-
way ca aly ic con e e s o ehicle exhaus ea men ,6 he oxida i e coupling o me hane, and he wa e -
gas shi eac ion.
In his s udy, we epo he syn hesis o pu e ce ium oxide nanopa icles and manganese-doped
ce ium oxide nanopa icles ia he co-p ecipi a ion me hod. The e ec o Mn doping on he s uc u al and
op ical p ope ies o CeO₂ is explo ed h ough a ious cha ac e iza ion echniques.
2. Ma e ials and Syn hesis Me hod
A. Me hod and Ma e ials
The p ecu so u ilized o make pu e ce ia NPs and Mn-doped ce ia NPs a e Ce ium ni a e hexahyd a e
[Ce(NO3)3∙6H2O] and Manganese ace a e [(CH3.COO)2Mn.4H2O]. The syn hesis was ca ied ou by co-
p ecipi a ion me hod. Co-p ecipi a ion me hod gi es high yield o end p oduc . All o he expe imen al
solu ions we e p epa ed wi h double dis illed wa e con aining 10% e hanol.
In luence o Mn doping on he c ys allini y and mo phology o ce ium oxide nanopa icles ..
Ma e ials Science: Ad ances in Syn hesis, Cha ac e iza ion and Applica ions (Vol. 1) - Digamba M. Sapkal,
Ha shal M. Bachha , Gau a Mahade Loha , Sanjay P. Khai na (Eds.)
ISBN: 978-93-95369-55-8 (pape back) 978-93-95369-46-6 (elec onic) | © 2025 Ad en Publishing.
213
Ma e ials Used
• Ce ium Ni a e Hexahyd a e – Ce(NO₃)₃·6H₂O Ac s as he ce ium p ecu so . I p o ides Ce³⁺ ions
necessa y o he o ma ion o ce ium oxide (CeO₂). I is a highly soluble sal , making i ideal o
aqueous syn hesis ou es.
• Manganese Ace a e Te ahyd a e – (CH₃COO)₂Mn·4H₂O Used as he dopan p ecu so o
in oduce Mn in o he ce ia la ice. P o ides Mn²⁺ ions which can pa ially subs i u e Ce⁴⁺ in he ce ia
c ys al s uc u e, po en ially modi ying i s elec onic, s uc u al, and ca aly ic p ope ies.
• Sol en – Double dis illed wa e con aining 10% e hanol ensu es high pu i y o he eac ion medium.
E hanol may aid in con olling he pa icle size and mo phology by in luencing he nuclea ion and
g ow h a es.
B. Syn hesis Me hod: Co-p ecipi a ion
A Co-p ecipi a ion me hod widely used and s aigh o wa d me hod o syn hesizing nanopa icles. This
me hod enables uni o m dis ibu ion o dopan ions. I O e s a high yield o he end p oduc . Ope a es
unde mild condi ions, ypically a ambien empe a u e o wi h mode a e hea ing.
Syn hesis P ocedu e
a) P epa a ion o P ecu so Solu ions
• Fo pu e CeO₂ nanopa icles: 0.3 M Ce(NO₃)₃·6H₂O was dissol ed in 50 mL o double dis illed
wa e con aining 10% e hanol. The solu ion was s i ed ho oughly using a magne ic s i e .
• Fo Mn-doped CeO₂ nanopa icles: Mn-doping solu ions we e p epa ed by dissol ing ei he 0.2
M o 0.3 M o (CH₃COO)₂Mn·4H₂O in he same sol en sys em. These we e added o he Ce
solu ion o doping, ensu ing a homogeneous mix u e.
b) P ecipi a ion P ocess
• NaOH solu ion (0.9 M) was added g adually o he Ce-only solu ion unde cons an s i ing o
ini ia e p ecipi a ion. The 0.9 M concen a ion co esponds o h ee imes he mola i y o he Ce
p ecu so , e lec ing he s oichiome y o he eac ion and he p esence o h ee ni a e ions pe
Ce³⁺ ion.
• Fo Mn-doped sys ems, bo h NaOH (0.9 M) and he p epa ed Mn solu ion we e added d opwise
and simul aneously o he ce ium ni a e solu ion unde con inuous s i ing. This ensu ed co-
p ecipi a ion o ce ium and manganese hyd oxides.
c) Reac ion Chemis y
The eac ion occu ing in he Ce-only sys em is:
Ce(NO₃)₃ 6H₂O+3NaOH→Ce(OH)₃+3NaNO₃+6H₂O
Nandkisho S. Sangle, Sangi a S. Mesh am
Ma e ials Science: Ad ances in Syn hesis, Cha ac e iza ion and Applica ions (Vol. 1) - Digamba M. Sapkal,
Ha shal M. Bachha , Gau a Mahade Loha , Sanjay P. Khai na (Eds.)
ISBN: 978-93-95369-55-8 (pape back) 978-93-95369-46-6 (elec onic) | © 2025 Ad en Publishing.
214
• A simila co-p ecipi a ion eac ion occu s o Mn-doped sys ems, wi h Mn²⁺ o ming Mn(OH)₂ in
he p ocess.
d) Aging and Sepa a ion
• The esul ing suspension was le undis u bed o 24 hou s o allow comple e p ecipi a ion and
o ma ion o a supe na an laye .
• The clea supe na an liquid was ca e ully emo ed using a d oppe .
e) D ying
• The emaining p ecipi a e was ans e ed o a ho ai o en and d ied a 150°C o 3–4 hou s o
emo e mois u e, esul ing in d y hyd oxide p ecu so s.
) G inding
• The d ied solid was g ound manually in a mo a and pes le o se e al hou s un il a ine,
uni o m powde was ob ained.
g) Calcina ion
• The ine powde was calcined a 300–400°C o 3–4 hou s in a mu le u nace.
• Du ing his he mal ea men :
o The hyd oxides we e con e ed o hei espec i e oxides (CeO₂ and Mn-doped CeO₂).
o The oxida ion s a e o Ce³⁺ was ans o med o Ce⁴⁺, o ming he s able luo i e-s uc u ed
CeO₂.
o Residual o ganic compounds (e.g., ace a e) and mois u e we e ully elimina ed.
o Calcina ion empe a u e was kep well below he mel ing poin o he ma e ial o p ese e
nano-sized ea u es and a oid sin e ing.
h) Obse a ions
Colo Change
o The pu e CeO₂ nanopa icles exhibi ed a ligh -yellow colo a e calcina ion.
o As he Mn doping concen a ion inc eased, he nanopa icles' colo u ned p og essi ely
da ke , indica ing success ul inco po a ion o Mn in o he ce ia ma ix and possible changes in
oxida ion s a es (e.g., Mn²⁺, Mn³⁺, Mn⁴⁺) and oxygen acancy o ma ion.
In luence o Mn doping on he c ys allini y and mo phology o ce ium oxide nanopa icles ..
Ma e ials Science: Ad ances in Syn hesis, Cha ac e iza ion and Applica ions (Vol. 1) - Digamba M. Sapkal,
Ha shal M. Bachha , Gau a Mahade Loha , Sanjay P. Khai na (Eds.)
ISBN: 978-93-95369-55-8 (pape back) 978-93-95369-46-6 (elec onic) | © 2025 Ad en Publishing.
215
3. Nanopa icles Cha ac e iza ion
a) Powde X- ay di ac ion
Pu e Ce ium
Doped Ce ium
Fig. 1. XRD g aph o pu e and doped ce ia
Powde X- ay di ac ion pa e ns o nanoma e ials we e eco ded using an X- ay di ac ome e
employing CuKα adia ion. The CuKα sou ce was ope a ed a 20kV- 40kV. Di ac ion da a we e eco ded
in a 2θ ange om 20° o 80° in 0.02° s eps o 0.6 s
The X- ay di ac ion (XRD) pa e n shown abo e co esponds o pu e ce ium oxide (CeO₂)
nanopa icles syn hesized ia he co-p ecipi a ion me hod. The di ac ion peaks obse ed a 2θ alues o
app oxima ely 28.5°, 33.1°, 47.5°, 56.3°, 59.1°, and 69.4° a e indexed o he c ys allog aphic planes
(111), (200), (220), (311), (400), and (331) espec i ely. These peaks a e in good ag eemen wi h he
s anda d da a om he JCPDS ca d, con i ming ha he syn hesized nanopa icles possess a luo i e-
ype cubic c ys al s uc u e, cha ac e is ic o CeO₂. The mos in ense peak a 28.5° co esponding o he
(111) plane indica es ha his is he p e e ed g ow h o ien a ion in he syn hesized sample. The sha p
and well-de ined peaks sugges ha he ma e ial is highly c ys alline, wi h minimal s uc u al de ec s o
amo phous con en . Fu he mo e, he absence o any addi ional o impu i y peaks con i ms he phase
pu i y o he syn hesized CeO₂ nanopa icles. This esul con i ms he success ul o ma ion o pu e
ce ium oxide wi h desi able c ys alline p ope ies, sui able o u he modi ica ion o applica ion in
ca aly ic and op ical ma e ials.
The X- ay di ac ion (XRD) pa e n shown illus a es he c ys alline s uc u e o Mn-doped
ce ium oxide (CeO₂) nanopa icles a wo di e en doping concen a ions: 0.1 M (blue cu e) and 0.2 M
( ed cu e). In bo h samples, p ominen di ac ion peaks appea a 2θ alues o app oxima ely 28.5°,
Nandkisho S. Sangle, Sangi a S. Mesh am
Ma e ials Science: Ad ances in Syn hesis, Cha ac e iza ion and Applica ions (Vol. 1) - Digamba M. Sapkal,
Ha shal M. Bachha , Gau a Mahade Loha , Sanjay P. Khai na (Eds.)
ISBN: 978-93-95369-55-8 (pape back) 978-93-95369-46-6 (elec onic) | © 2025 Ad en Publishing.
216
47.5°, 56.3°, 59.1°, and 69.4°, which co espond o he (111), (220), (311), (400), and (331) planes,
espec i ely. These peaks ma ch well wi h he s anda d JCPDS ca d o luo i e- ype cubic CeO₂,
indica ing ha manganese doping does no al e he undamen al c ys al s uc u e o ce ium oxide. The
absence o seconda y o impu i y peaks con i ms ha Mn ions a e success ully inco po a ed in o he CeO₂
la ice wi hou o ming sepa a e manganese oxide phases. A compa ison be ween he wo doping le els
shows a sligh educ ion in peak in ensi y and b oadening wi h inc easing Mn con en , pa icula ly in he
0.2 M doped sample. This sugges s a educ ion in c ys alli e size and possible la ice s ain o de ec
o ma ion, which a e ypical e ec s o dopan subs i u ion in he hos la ice. The sligh b oadening o
peaks may also indica e inc eased diso de wi hin he c ys al s uc u e due o Mn inco po a ion. O e all,
he XRD analysis con i ms ha bo h 0.1 M and 0.2 M Mn-doped CeO₂ nanopa icles main ain a
c ys alline luo i e s uc u e, wi h Mn doping sub ly in luencing he c ys allini y and pa icle size
depending on he dopan concen a ion.
b) Ul a iole Di use Re lec ance Spec oscopy (UV-DRS)
UV-di use e lec ance spec oscopy (DRS) is a ype o su ace analysis. As a p obing medium, i employs
ul a iole (UV) ligh . Ligh in e ac s wi h "s ongly abso bing ma e ials" such as me als, alloys,
semiconduc o s, and so on in he i s 10-20 nm.
Fig. 2. Abso bance o UV-DRS o pu e and doped ce ia
The UV–Visible Di use Re lec ance Spec oscopy (UV-DRS) g aph (Fig. 2) p esen ed illus a es
he op ical abso p ion beha io o pu e ce ium oxide (CeO₂) and Mn-doped CeO₂ nanopa icles a wo
di e en doping concen a ions: 0.1 M and 0.2 M. The abso bance spec a e eal a no able shi in he
op ical p ope ies as a esul o Mn doping. Pu e CeO₂ nanopa icles (black cu e) show a dis inc
In luence o Mn doping on he c ys allini y and mo phology o ce ium oxide nanopa icles ..
Ma e ials Science: Ad ances in Syn hesis, Cha ac e iza ion and Applica ions (Vol. 1) - Digamba M. Sapkal,
Ha shal M. Bachha , Gau a Mahade Loha , Sanjay P. Khai na (Eds.)
ISBN: 978-93-95369-55-8 (pape back) 978-93-95369-46-6 (elec onic) | © 2025 Ad en Publishing.
217
abso p ion edge in he ul a iole egion, a ound 380–400 nm, which is ypical o CeO₂ wi h a wide band
gap o app oxima ely 3.2 eV. Upon doping wi h Mn, a signi ican enhancemen in isible ligh abso p ion
is obse ed.
The 0.1 M Mn-doped sample (blue cu e) exhibi s a mode a e ed shi in he abso p ion edge,
indica ing a sligh na owing o he band gap and imp o ed abso p ion in o he isible egion. This e ec
becomes mo e p onounced in he 0.2 M Mn-doped sample ( ed cu e), which shows a b oade and highe
abso bance ex ending u he in o he isible ange (up o ~700 nm), con i ming a mo e subs an ial
educ ion in he band gap.
This p og essi e ed shi and inc ease in abso bance wi h highe Mn con en can be a ibu ed o
he in oduc ion o impu i y ene gy le els wi hin he band gap and he o ma ion o oxygen acancies o
de ec s a es, which p omo e elec onic ansi ions unde lowe ene gy (longe wa eleng h) ligh . O e all,
he UV-DRS esul s demons a e ha Mn doping e ec i ely enhances he isible ligh abso p ion
capabili y o CeO₂ nanopa icles, making hem mo e sui able o applica ions in pho oca alysis, sola
ene gy con e sion, and o he op oelec onic ields.
Fig. 3. Re lec ance o UV-DRS o pu e and doped ce ia
The abo e g aph (Fig. 3) shows he UV–Visible Di use Re lec ance Spec a (UV-DRS) o pu e
CeO₂ nanopa icles and Mn-doped CeO₂ nanopa icles a 0.1 M and 0.2 M doping concen a ions, plo ed
as % e lec ance (%R) s. wa eleng h. This e lec ance da a p o ides insigh in o he op ical band gap and
ligh in e ac ion beha io o he ma e ials. The pu e CeO₂ sample (black cu e) exhibi s high e lec ance
in he isible egion, pa icula ly be ween 400 nm and 800 nm, indica ing ha i abso bs p ima ily in he
UV egion and e lec s mos isible ligh . This co esponds o i s la ge band gap (~3.2 eV) and limi ed
u ili y in isible ligh -d i en applica ions. Howe e , a signi ican dec ease in e lec ance is obse ed in he
Mn-doped samples, especially he 0.2 M Mn-doped CeO₂ ( ed cu e), which shows he lowes e lec ance
Nandkisho S. Sangle, Sangi a S. Mesh am
Ma e ials Science: Ad ances in Syn hesis, Cha ac e iza ion and Applica ions (Vol. 1) - Digamba M. Sapkal,
Ha shal M. Bachha , Gau a Mahade Loha , Sanjay P. Khai na (Eds.)
ISBN: 978-93-95369-55-8 (pape back) 978-93-95369-46-6 (elec onic) | © 2025 Ad en Publishing.
218
ac oss he en i e spec um. This indica es a highe abso p ion o ligh , pa icula ly in he isible egion, as
Mn doping in oduces de ec le els o in e media e s a es wi hin he band gap. The 0.1M Mn-doped
sample (blue cu e) shows an in e media e beha io , wi h e lec ance lowe han ha o pu e CeO₂ bu
highe han he 0.2M doped sample. The dec ease in e lec ance wi h inc easing Mn concen a ion
con i ms he enhanced op ical abso p ion due o Mn inco po a ion, which esul s in a na owing o he
e ec i e band gap. This enhancemen in isible ligh abso p ion is consis en wi h he abso bance da a
and makes Mn-doped CeO₂ mo e sui able o pho oca aly ic and op oelec onic applica ions, whe e
e icien ligh ha es ing is essen ial.
c) Field Emission Scanning Elec on Mic oscopy
Field Emission Scanning Elec on Mic oscopy FESEM o nanopa icles we e pe o med by using “NOVA
NANOSEM NPEP450”. This ins umen o e s high esolu ion and excellen con as , ex ended
accele a ing ol age anging om 50 eV o 30 kV, a wide magni ica ion ange. The imaging used a ious
accele a ion ol ages, beam cu en s, wo king dis ance and ape u e se ing o ob ain he highes esolu ion
possible. The below shows FESEM images o pu e and doped ce ia.
Fig. 4. FESEM o pu e ce ium
The mo phology o pu e CeO₂ nanopa icles, as e ealed by he FESEM images, shows a highly
agg ega ed and densely packed s uc u e, ypical o nanopa icles syn hesized ia he co-p ecipi a ion
me hod. In he low-magni ica ion image (le ), he su ace appea s ough and g anula , sugges ing he
p esence o nanopa icle clus e s. As he magni ica ion inc eases (middle image), mo e dis inc pa icle
bounda ies become isible. The pa icles appea o be i egula in shape, wi h ough su aces and
occasional signs o po ous egions o oids be ween agg ega es. This sugges s ha while p ima y pa icles
a e nanoscale, hey end o agglome a e, likely due o high su ace ene gy and Van de Waals o ces. In
he high-magni ica ion image ( igh ), whe e pa icle size measu emen s a e p o ided, he nanopa icles
exhibi sizes anging om app oxima ely 20 o 30 nm. This nanoscale dimension is consis en wi h he
c ys alli e size de i ed om XRD analysis and con i ms he nanos uc u ed na u e o he ma e ial. The
p esence o well-de ined bu closely packed g ains indica es good c ys allini y bu also sugges s some
le el o pa icle coa sening o sin e ing, possibly in oduced du ing he d ying o calcina ion s eps.
O e all, he FESEM images con i m ha pu e CeO₂ nanopa icles a e polyc ys alline, i egula ly
shaped, and wi hin he nanoscale ange, wi h a endency owa d agglome a ion. This mo phology is
In luence o Mn doping on he c ys allini y and mo phology o ce ium oxide nanopa icles ..
Ma e ials Science: Ad ances in Syn hesis, Cha ac e iza ion and Applica ions (Vol. 1) - Digamba M. Sapkal,
Ha shal M. Bachha , Gau a Mahade Loha , Sanjay P. Khai na (Eds.)
ISBN: 978-93-95369-55-8 (pape back) 978-93-95369-46-6 (elec onic) | © 2025 Ad en Publishing.
219
sui able o applica ions equi ing high su ace a ea, such as ca alysis, al hough su ace modi ica ion o
doping (e.g., wi h Mn) may be equi ed o op imize p ope ies u he .
Fig. 5. FESEM o manganese doped ce ium
The FESEM mic og aphs e eal ha he Mn-doped CeO₂ nanopa icles exhibi a dis inc
mo phological e olu ion and su ace s uc u e compa ed o pu e ce ia. In he low-magni ica ion image
( op), he pa icles a e agg ega ed and densely packed, wi h a somewha g anula su ace ex u e. This
agg ega ion is ypical o nanopa icles and can be a ibu ed o hei high su ace ene gy and s ong
in e pa icle in e ac ions. As he magni ica ion inc eases (middle image), he pa icles begin o show mo e
de ined and lowe -like o laye ed s uc u es, indica ing a po en ial in luence o Mn doping on c ys al
g ow h pa e ns and su ace ene gy dis ibu ion du ing syn hesis. A he highes magni ica ion (bo om
image), he indi idual pa icles a e clea ly isible, and size measu emen s show nanopa icle dimensions
anging be ween 20 o 37 nm. The pa icles appea pla e-like and closely packed, wi h ela i ely sha p
edges, which may sugges a deg ee o aniso opic g ow h. The obse ed size ange aligns well wi h he
c ys alli e sizes es ima ed om XRD analysis, suppo ing he nanoc ys alline na u e o he samples. The
inco po a ion o Mn appea s o in luence bo h pa icle shape and su ace oughness, po en ially
enhancing su ace a ea and ac i e si es o pho oca aly ic o senso applica ions. O e all, he FESEM
images con i m ha Mn doping al e s he su ace mo phology o CeO₂, leading o mo e de ined,
smalle , and oughe pa icles compa ed o pu e CeO₂. These s uc u al modi ica ions could signi ican ly
impac he op ical and ca aly ic beha io o he nanopa icles.
Applica ions o Pu e and Mn-Doped CeO₂ Nanopa icles
o Pho oca alysis: Enhanced isible ligh abso p ion due o Mn doping makes hem sui able o
pho oca aly ic deg ada ion o pollu an s in wa e and ai pu i ica ion sys ems.
o Sola Ene gy Con e sion: Imp o ed ligh abso p ion p ope ies suppo hei use in sola cells
and pho o-elec ochemical cells o ene gy ha es ing.
o Ca alysis: CeO₂ is widely used in au omo i e ca aly ic con e e s ( h ee-way ca alys s). Mn
doping inc eases su ace a ea and ac i e si es, enhancing edox and oxida ion eac ions.
o Senso s: Thei high su ace eac i i y and conduc i i y make hem ideal o gas sensing and
en i onmen al moni o ing.
