Table 1.

Selected examples of catalytic applications of TiO₂@clay and ZnO@clay nanoarchitectures.

clay-based nanoarchitectures		photodegradation	other applications
clay component	semiconductor component
kaolinite	TiO2	Kutláková et al. (2011) [94]; Zhang et al. (2011) [95]; Chong et al. (2009) [96]; Barbosa et al. (2015) [98]	CO2 reduction, Kočí et al. (2011) [97]
kaolinite	ZnO	M. Kutláková et al. (2015) [172]	antibacterial activity, Dĕdková et al. (2016) [173]
halloysite	TiO2	Papoulis et al. (2013) [174]; Wang et al. (2011) [123]; Li et al. (2015) [175]; Du et al. (2014) [176]; Papoulis et al. (2010) [114]	—
hectorite	TiO2	Ma et al. (2009 & 2010) [103,108], Kibanova et al. (2009) [101]; Belessi et al. (2007) [102]	—
Laponite®	TiO2	Zhu et al. (2002) [177]	—
Ce–Ti-pillared Laponite®	TiO2	Lin et al. (2010) [178]	—
Zr–Ti-pillared Laponite®	TiO2	Lin et al. (2011) [179]	—
stevensite	TiO2	Bouna et al. (2014) [180]	—
beidellite	TiO2	Rhouta et al. (2015) [99]	—
Ti-pillared beidellite	TiO2	—	cracking of cumene, Swarnakar et al. (1996) [181]
TiO2-pillared saponite	TiO2	—	degradation of NOx gas, Nikolopoulou et al. (2009) [182]
montmorillonite, bentonite and related smectites	TiO2	Sun et al. (2015) [105]; Manova et al. (2010) [106]; Rossetto et al. (2010) [104]	—
montmorillonite, bentonite and related smectites	ZnO	Fatimah et al. (2011) [89]; Khumchoo et al. (2016) [46]; Ye et al. (2015) [120]; Akkari et al. (2016) [118]; Xu et al. (2014) [124]
montmorillonite and related smectites	TiO2/ZnO	Bel Hadjltaief et al. (2016) [158]; Tobajas et al. (2017) [159]
montmorillonite (CTA-organoclay)	ZnO	—	antibacterial activity, Gu et al. (2015) [117];
lightweight expanded clay aggregates (LECA)	TiO2/ZnO	—	removal of ammonia from wastewater; Mohammadi et al. (2016) [161]
montmorillonite–kaolinite	TiO2	—	removal of Pb(II), Cu(II), Zn(II), and Cd(II); Đukić et al. (2015) [183]
bentonite	TiO2	—	Degradation of volatile organic compounds (VOCs); Mishra et al.(2018) [184]
rectorite	TiO2	Bu et al. (2010) [185]; Zhang et al. (2011) [186]; Yang et al. (2012) [187]	—
rectorite	ZnO	Li et al. (2014) [188]	—
rectorite	TiO2/ZnO	Wang et al. (2018) [163]	—
sepiolite	TiO2	Aranda et al. (2008) [109];Suárez et al. (2008) [112]; Ökte & Sayınsöz (2008) [113]; Du et al. (2015) [189]a; Zhou et al. (2017) [190]	photoreforming of methanol, Pérez-Carvajal et al. (2016) [131]b
sepiolite	ZnO	Xu et al. (2010) [90]; Akkari et al. (2016) [118]	removal of H2S by chemisorption, Portela et al. (2015) [122]
sepiolite	TiO2/ZnO	Vaizoğullar (2017) [160]
palygorskite	TiO2	Zhang et al. (2011) [191]c; Bouna et al. (2011) [111]; Papoulis et al. (201) [115] Stathatos et al. (2012) [116]	degradation of NOx gas, Papoulis et al. (2010) [114]
palygorskite	ZnO	—	antibacterial activity, Huo and Yang (2010) [121]

^acontaining Ag₂O/TiO₂; ^bPt- or Pd-doped TiO₂; ^ccontaining SnO₂/TiO₂.