Investigation of the Use of Phosphate Modified rGO and rGO-Alginate Microspheres in Lanthanum and Cerium Adsorption

Conference paper > Summary Text · 2026

Authors: Şenol SERT, Aydın

20th NANOSCIENCE AND NANOTECHNOLOGY TR-20 CONFERENCE, Türkiye, İzmir, International, Verbal, Summary Text, 2026-2026, pp 171-171

Summary

<p>Rare&nbsp;earth&nbsp;elements&nbsp;are&nbsp;strategically&nbsp;important&nbsp;materials&nbsp;that&nbsp;are&nbsp;widely&nbsp;used&nbsp;in&nbsp;electronic&nbsp;systems,&nbsp;energy&nbsp;technologies,&nbsp;catalytic&nbsp;applications,</p><p>&nbsp;and&nbsp;defense&nbsp;industries.&nbsp;In&nbsp;particular,&nbsp;the&nbsp;expanding&nbsp;industrial&nbsp;utilization&nbsp;of&nbsp;lanthanum&nbsp;and&nbsp;cerium&nbsp;has&nbsp;increased&nbsp;the&nbsp;need&nbsp;for&nbsp;efficient&nbsp;and</p><p></p><p>environmentally&nbsp;friendly&nbsp;recovery&nbsp;methods&nbsp;for&nbsp;these&nbsp;elements&nbsp;[1.&nbsp;Adsorption,&nbsp;which&nbsp;is&nbsp;a&nbsp;low-cost.&nbsp;practical,&nbsp;and&nbsp;highly&nbsp;efficient&nbsp;technique,</p><p></p><p>has&nbsp;been&nbsp;employed&nbsp;for&nbsp;the&nbsp;removal&nbsp;of&nbsp;La&nbsp;and&nbsp;Ce&nbsp;from&nbsp;aqueous&nbsp;solutions.&nbsp;In&nbsp;this&nbsp;study,&nbsp;reduced&nbsp;graphene&nbsp;oxide&nbsp;(rGO)&nbsp;was&nbsp;synthesized&nbsp;in&nbsp;a</p><p></p><p>single&nbsp;step&nbsp;by&nbsp;applying&nbsp;thermal&nbsp;reatment&nbsp;to&nbsp;the&nbsp;ethylene&nbsp;glycol&nbsp;solution&nbsp;obtained&nbsp;from&nbsp;the&nbsp;HaSO4&nbsp;hydrolysis&nbsp;of&nbsp;waste&nbsp;PET&nbsp;botles.&nbsp;This</p><p></p><p>approach&nbsp;aims&nbsp;not&nbsp;only&nbsp;to&nbsp;valorize&nbsp;plastic&nbsp;waste&nbsp;but&nbsp;also&nbsp;to&nbsp;develop&nbsp;an&nbsp;economical&nbsp;and&nbsp;environmentally&nbsp;friendly&nbsp;synthesis&nbsp;route&nbsp;(21.&nbsp;Due&nbsp;to&nbsp;its</p><p></p><p>high&nbsp;surface&nbsp;area,&nbsp;chemical&nbsp;stability,&nbsp;and&nbsp;suitability&nbsp;for&nbsp;surface&nbsp;functionalization,&nbsp;rGO&nbsp;was&nbsp;selected&nbsp;as&nbsp;the&nbsp;adsorbent&nbsp;material&nbsp;and&nbsp;modified</p><p></p><p>with&nbsp;phosphate&nbsp;functional&nbsp;groups&nbsp;to&nbsp;enrich&nbsp;its&nbsp;active&nbsp;binding&nbsp;sites&nbsp;for&nbsp;adsorption.&nbsp;In&nbsp;addition,&nbsp;the&nbsp;use&nbsp;of&nbsp;phosphate-modified&nbsp;rGO&nbsp;in&nbsp;the&nbsp;form</p><p></p><p>of&nbsp;sodium&nbsp;alginate-based&nbsp;microbeads&nbsp;was&nbsp;investigated,&nbsp;and&nbsp;the&nbsp;biocompatible&nbsp;structure&nbsp;of&nbsp;alginate,&nbsp;rich&nbsp;in&nbsp;carboxyl&nbsp;groups,&nbsp;was&nbsp;found&nbsp;to</p><p></p><p>contribute&nbsp;positively&nbsp;to&nbsp;adsorption&nbsp;performance&nbsp;[31&nbsp;In&nbsp;this&nbsp;study,&nbsp;the&nbsp;adsorption&nbsp;performance&nbsp;of&nbsp;phosphate-modi&nbsp;fied&nbsp;reduced&nbsp;graphene&nbsp;oxide</p><p></p><p>(GO)&nbsp;for&nbsp;the&nbsp;removal&nbsp;of&nbsp;La&nbsp;(II)&nbsp;and&nbsp;Ce&nbsp;(ll)&nbsp;ions&nbsp;was&nbsp;evaluated.&nbsp;The&nbsp;results&nbsp;demonstrated&nbsp;that&nbsp;the&nbsp;optimum&nbsp;pH&nbsp;value&nbsp;for&nbsp;both&nbsp;metal&nbsp;ions&nbsp;was</p><p></p><p>4,&nbsp;while&nbsp;the&nbsp;optimum&nbsp;contact&nbsp;time&nbsp;was&nbsp;90&nbsp;min.&nbsp;The&nbsp;maximum&nbsp;adsorption&nbsp;capacities&nbsp;were&nbsp;determined&nbsp;as&nbsp;29.31&nbsp;mg&nbsp;g&nbsp;for&nbsp;Ce&nbsp;(I)&nbsp;and&nbsp;37.90</p><p></p><p>mg&nbsp;g-&nbsp;for&nbsp;La&nbsp;(I).&nbsp;Isothem&nbsp;analyses&nbsp;revealed&nbsp;that&nbsp;the&nbsp;Langmuir&nbsp;model&nbsp;provided&nbsp;the&nbsp;best&nbsp;fit&nbsp;to&nbsp;the&nbsp;experimental&nbsp;data,&nbsp;indicating&nbsp;that</p><p></p><p>adsorption&nbsp;predominantly&nbsp;occured&nbsp;through&nbsp;monolayer&nbsp;coverage.&nbsp;Kinetic&nbsp;studies&nbsp;showed&nbsp;a&nbsp;better&nbsp;agreement&nbsp;with&nbsp;the&nbsp;Pseudo-Second-Order</p><p></p><p>(PSO)&nbsp;kinetic&nbsp;model,&nbsp;suggesting&nbsp;that&nbsp;chemical&nbsp;interactions&nbsp;played&nbsp;a&nbsp;significant&nbsp;role&nbsp;in&nbsp;the&nbsp;adsorption&nbsp;mechanism.&nbsp;For&nbsp;alginate-rGO&nbsp;micro</p><p></p><p>beads&nbsp;prepared&nbsp;in&nbsp;different&nbsp;weight&nbsp;ratios,&nbsp;pH&nbsp;optimization&nbsp;experiments&nbsp;indicated&nbsp;that&nbsp;the&nbsp;adsorbent&nbsp;containing&nbsp;40&nbsp;wt.%&nbsp;rGO&nbsp;achieved</p><p></p><p>adsorption&nbsp;capacities&nbsp;of&nbsp;25.34&nbsp;mg&nbsp;g&nbsp;for&nbsp;Ce&nbsp;(u)&nbsp;and&nbsp;24.86&nbsp;mg&nbsp;g-&nbsp;for&nbsp;La&nbsp;(III)&nbsp;at&nbsp;pH&nbsp;5.&nbsp;Structural&nbsp;and&nbsp;surface&nbsp;characteristics&nbsp;of&nbsp;the&nbsp;adsorbents</p><p></p><p>were&nbsp;comprehensively&nbsp;investigated&nbsp;using&nbsp;SEM,&nbsp;FTIR,&nbsp;and&nbsp;XPS&nbsp;analyses.&nbsp;</p>

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