Nanometer-thick [(FPEA)₂PbX₄; X = I and Br] 2D halide perovskite based thin films for pollutant detection and nonconventional photocatalytic degradation

Abstract

Application of three-dimensional (3D)-halide perovskites (HaP) in photocatalysis encourages the new exercise with two-dimensional (2D) HaP based thin-films for photocatalytic degradation of dye. The reduced dimensionality to 2D-HaPs, with a...

Effect of ‘Fluorophenylammonium’ and ‘Fluorophenethylammonium’ as Spacer on the Photo(electro)chemical and Photocatalytic Behaviour of Mixed Halide Based Layered Perovskites

“…MBT has characteristics peak at 325 nm, which decreases as a function of time, and a new peak at 274 nm starts to increase (Figure S9a and Figure S9b, Supporting Information). The increase in the intensity of the 274 nm peak indicates the formation of S−S coupled product 2,2′‐dithiobis(benzothiazole) disulfide [MBTS] due to oxidation of MBT [33,62–64] . The possible mechanism of this photocatalytic oxidative transformation of MBT to MBTS (Scheme S1; Supporting Information) was discussed in our previous study.…”

“…(b) Schematic of 2D‐PbHaPs coated over FTO with various interfaces and the processes occurring in the system. (c) Chronoamperometry of FTO/c‐TiO 2 /m‐TiO 2 /(FPA) 2 PbI 2 Br 2 and FTO/c‐TiO 2 /m‐TiO 2 /(FPEA) 2 PbI 2 Br 2 [33] under 1 Sun under multiple on‐off cycles. (d) linear sweep voltammetry of FTO/c‐TiO 2 /m‐TiO 2 /(FPA) 2 PbI 2 Br 2 and FTO/c‐TiO 2 /m‐TiO 2 /(FPEA) 2 PbI 2 Br 2 under dark and illuminated condition (1 Sun) using a solar simulator.…”

“…The increase in the intensity of the 274 nm peak indicates the formation of SÀ S coupled product 2,2'-dithiobis(benzothiazole) disulfide [MBTS] due to oxidation of MBT. [33,[62][63][64] The possible mechanism of this photocatalytic oxidative transformation of MBT to MBTS (Scheme S1; Supporting Information) was discussed in our previous study. Briefly, the photogenerated holes at the perovskite surface oxidize MBT, which gives rise to protons (H + ) and thiyl radicals (⋅SH).…”

“…reported photocatalytic activity of FAPbBr 3 /TiO 2 ‐based composite systems towards oxidation of benzylic alcohols in toluene solution. Recently, we have demonstrated that 2D‐PbHaPs films‐(FPEA) 2 PbX 4 with various X sites (X=I and a mixture of I/Br) can be efficiently used for photocatalysis application toward S−S coupling reaction and detection of toxic molecules [33] . The objective of this work was to perform a comparative study between two different two‐dimensional mixed halide‐based perovskites [R 2 PbX 2 X′ 2 : with R=4‐fluorophenethylammonium (FC 6 H 4 (CH 2 ) 2 NH 3 + ; mentioned as FPEA in this study and X=I and X′=Br) and R′ 2 PbX 2 X′ 2 : R′=4 fluorophenylammonium (FC 6 H 4 NH 3 + ; mentioned as FPA in this study and X=I and X′=Br)] as a function of the ‘spacer’ (Scheme 1).…”

Effect of formamidinium (FA) ions on mixed ‘A’-site based bromide perovskite (APbBr3) thin films

“…After that, the m-TiO 2 film was annealed at 500 1C for 2 hours. 24 Fabrication of the perovskite film. Initially, 1.1 M concentrated precursor solutions of MA 0.9 Cs 0.1 PbBr 3 and FA 0.5 MA 0.4 -Cs 0.1 PbBr 3 perovskites were prepared from the corresponding salts (FABr, MABr, CsBr and PbBr 2 ).…”