Fig 1

(a) Basic principles of photocatalysis on semiconductor 105. Reproduced with permission from American Chemical Society. (b) Mechanisms of photocatalytic overall water splitting 32. Reproduced with permission from American Chemical Society."

Fig 2

(a) Element composition of reported perovskite oxide-based photocatalysts for CO2 reduction 106. Reproduced with permission from Wiley-VCH. (b) The structure of ABO3."

Fig 3

Schematic crystal structures of (a) the monoclinic NaTaO3; (b) the orthorhombic NaTaO3 110. Reproduced with permission from Elsevier. (c) Schematic crystal structures of cubic, orthorhombic and tetragonal KNbO3 109. Reproduced with permission from Royal Society of Chemistry."

Fig 4

(a) Schematic of photoexcitation in a photocatalyst and the redox potential values for the formation of different products at pH = 0 vs. NHE. (b) Band gap and band positions of pristine and doped perovskite materials 13. Reproduced with permission from American Chemical Society."

Fig 5

Schematic for bandgap engineering of semiconductors. The band structure and optical absorption curves of (a) an intrinsic semiconductor, (b) doping-induced intraband energy states, (c) doping-induced band gap narrowing and (d) degenerate doping-induced LSPR 137. Reproduced with permission from Royal Society of Chemistry."

Fig 6

Band structure of various types of heterojunctions in a photocatalytic hybrid composite: (a) Type Ⅱ heterojunction, (b) p-n junction, (c) Schottky junction, (d) Z-scheme heterojunction 11. Reproduced with permission from Elsevier."

Fig 7

(a) Schematic representation of LaFeO3 preparation 152. Reproduced with permission from Elsevier. (b) Schematic process for the preparation of PFN powders 153. Reproduced with permission from Elsevier. (c) Proposed synthesis process of SrFe0.5Ta0.5O3 nanoparticles via the low-temperature solvothermal method 154. Reproduced with permission from Elsevier."

Table 1

Summary of perovskite oxide based materials for photocatalytic CO2 conversion."

Table 2

Electrochemical reactions involved in CO2 reduction with water and their corresponding reduction potential E0 106."

Fig 8

(a) Band structures for a selection of perovskite oxides and oxynitrides and the corresponding redox potentials involved in photocatalytic CO2 reduction 169. Reproduced with permission from American Chemical Society. (b) Mechanism illustration of the photocatalytic CO2 reduction process 191. Reproduced with permission from Elsevier."

Fig 9

(a) The FTIR spectra of gaseous feed, and products of CO2 + CH4 photocatalysis after 4 h visible irradiation on BZ11 (the powders containing BiFeO3 : ZnO with 1 : 1) sample. (b) The possible reaction mechanism of C1 products from CO2 reduction 52. Reproduced with permission from Elsevier."

Fig 10

(a) Band structure scheme for as-prepared NaTaO3-C photocatalyst and samples annealed from 500 ℃ to 700 ℃ 115. Reproduced with permission from Elsevier. (b) Schematic representations of light reflections and refractions in hollow CaTiO3 201. Reproduced with permission from Elsevier."

Fig 11

(a) Ag2CrO4/Ag/BiFeO3@RGO heterojunction showing movement of charge carriers; Photocatalytic CO2 reduction under visible light. (b) Yield of CH4. (c) Yield of CO. The band energy schematic diagram of BiFeO3 and ZnO 203. Reproduced with permission from Elsevier. (d) Before contact, and (e) after making p-n heterojunction along with the mechanism of visible light induced photoreduction of CO2 52. Reproduced with permission from Elsevier."

Fig 12

(a) Low-magnification and (b) high-magnification SEM images of LaCoO3 sample 103. Reproduced with permission from Royal Society of Chemistry."

Fig 13

(a) SEM image of Pt2/3DOM-SrTiO3. (b, c) TEM and HRTEM images of 3DOM SrTiO3 55. Reproduced with permission from Elsevier."

Fig 14

Schematic of photocatalytic CO2 reduction with H2O to CO and CH4 products over Ptn/3DOM-SrTiO3 catalysts 55. Reproduced with permission from Elsevier."

Table 3

Summary of perovskite oxide based materials for photocatalytic water splitting."

Fig 15

(a) Basic principle of photocatalytic hydrogen and oxygen production via water splitting. (b) Energy band structure and energy level of photocatalytic decomposition of water 241. Reproduced with permission from Elsevier."

Fig 16

(a) Water splitting activity of SrTiO3 photocatalysts. SEM images of SrTiO3 particles: (b) S TO(pristine), (c) STO(flux-Y), and (d) STO(flux-Al) 245. Reproduced with permission from Royal Society of Chemistry."

Fig 17

The morphology engineering strategy for SrTiO3 nanocrystals. (a-c) The morphology of 6-facet SrTiO3 nanocrystals. (d) The structure of the (001) facet of SrTiO3. (e) The schematic description of changing SrTiO3 nanocrystals from 6-facet to 18-facet. (f-h) The morphology of 18-facet SrTiO3 nanocrystals. (ⅰ) The structure of the (001) facet of SrTiO3 246. Reproduced with permission from Royal Society of Chemistry."

Fig 18

(a) H2 (●) and O2 (○) evolution from bulk NiOSrTiO3 (solid line), 30 nm NiOSrTiO3 (dashed line), and 6.5 nm NiOSrTiO3 (dotted line) in 50 mL of water at pH = 7 under full spectrum irradiation (~26.3 mmol?L?1?cm-2 in the UV from 250 to 380 nm) 247. Reproduced with permission from American Chemical Society. (b) Crystal structures of layered perovskites 248. Reproduced with permission from Elsevier. (c) Time course of hydrogen evolution over (●) Rh(0.03)-doped Ca-Nb-O sheets, (■) Rh(0.03)-doped KCa2Nb3O10, and (▲) Rh(1.0 wt%)-loaded Ca-Nb-O sheet. (d) Crystal structure of Rh-doped calcium niobate nanosheet prepared by exfoliation of layered KCa2Nb3-xRhxO10?δ and photocatalytic reaction model in water/methanol system 116. Reproduced with permission from American Chemical Society. (e) Possible charge transfer in the CN/KCTO 2D-2D heterojunction photocatalysts and the corresponding mechanism for their excellent photocatalytic activity 249. Reproduced with permission from Royal Society of Chemistry."

Fig 19

(a) Long-term stability test of LNO-RGO composite for 36 h. (b) Photocatalytic hydrogen production mechanism of LNO-RGO nanoreactor 144. Reproduced with permission from Elsevier."

Table 4

Summary of perovskite oxide based materials for photocatalytic N2 fixation."

Fig 20

(a) Schematic of photocatalytic N2 fixation to NH3 on a semiconductor based photocatalyst 293. Reproduced with permission from Elsevier. (b) Generic mechanisms for nitrogen reduction to ammonia on heterogeneous catalysts 294. Reproduced with permission from Elsevier."

Fig 21

(a) Schematic illustration of the formation mechanism of Or-Bi/Bi2WO6 275. Reproduced with permission from Royal Society of Chemistry. (b) Possible mechanisms in Ag/KNbO3 composite under simulated sunlight and visible light 274. Reproduced with permission from American Chemical Society. (c) The photocatalytic mechanism of TiO2/SrTiO3/g-C3N4 heterojunctions under simulated sunlight irradiation. (d) The amount of nitrogen fixation per gram of sample under simulated sunlight irradiation 121. Reproduced with permission from Royal Society of Chemistry. (e) Charge transfer mechanism through the p-n junction in the MCeO2-BiFeO3 composite 273. Reproduced with permission from American Chemical Society. (f) Schematic illustration of the design and preparation of the as-fabricated BP hybrid photocatalyst 276. Reproduced with permission from American Chemical Society."

Fig 22

Schematic of the general mechanism for photocatalytic pollutant degradation 13. Reproduced with permission from American Chemical Society."

Fig 23

Illustration of energy band for pristine BiFeO3 and hydrogenated BiFeO3 with oxygen vacancies 309. Reproduced with permission from Elsevier."

Fig 24

Reaction kinetics for NaNbO3 and reduced NaNbO3 in different temperature 310. Reproduced with permission from Royal Society of Chemistry."

Fig 25

BET surface area plots for (a) g-C3N4, (b) CaTiO3 and (c) CTCN heterojunction. (d) Mechanism of degradation of pollutants under sunlight irradiation using the CTCN heterojunction photocatalyst. (e) Degradation percentage plots of RhB with sunlight irradiation after 120 min of irradiation 24. Reproduced with permission from Beilstein-Institut Zur Forderung der Chemischen Wissenschaften."

Fig 26

Electronic band structure (a) and density of states (b) of barium bismuthate sample 314. Reproduced with permission from Royal Society of Chemistry."

Fig 27

(a) Calculated band structures, total density of states, and partial density of states of constituent elements of Sr2TiO3F2, and Fermi level is marked by dotted orange line; (b) Density contour maps of Sr2TiO3F2 at VBM and CBM 33. Reproduced with permission from Elsevier."

Fig 28

Local structures of optimized configurations for (a) C-doped, (b) Si-doped, (c) N-doped, (d) P-doped, (e) S-doped, (f) Se-doped, (g) F-doped, (h) Cl-doped, (ⅰ) Br-doped and (j) I-doped BaTiO3 with X@O 315. Reproduced with permission from Elsevier."

Fig 29

Total density of states (a) and projected density of states (b) for C-doped, Si-doped, N-doped, P-doped, S-doped and Se-doped systems. The vertical dashed line represents the top of the valence band of the bulk BaTiO3 as the reference level 315. Reproduced with permission from Elsevier."

Fig 30

Schematic representation of the calculated VBM and CBM positions of X-doped BaTiO3 with respect to those of pristine BaTiO3 (a) with X@O and (b) with X@Ti 315. Reproduced with permission from Elsevier."