S T R U C T U R E O F M A T E R I A L S

S C I E N T I F I C H I G H L I G H T S

1 4 0 H I G H L I G H T S 2 0 2 1 I

PRINCIPAL PUBLICATION AND AUTHORS

COx-free hydrogen production from ammonia mimicking the activity of Ru catalysts with unsupported Co-Re alloys, K. Kirste (a), K.McAulay (b), T.E. Bell (c), D. Stoian (d), S. Laassiri (b,e), A. Daisley (b), J.S.J. Hargreaves (b), K. Mathisen (a), L. Torrente-Murciano (c), Appl. Catal. B: Environ. 280, 119405 (2021); https:/doi.org/10.1016/j.apcatb.2020.119405. (a) Norwegian University of Science and Technology (Norway) (b) University of Glasgow (UK) (c) University of Cambridge (UK) (d) ESRF (e) Mohamed VI Polytechnic University (Morocco)

REFERENCES

[1] T.E. Bell & L. Torrente-Murciano, Top. Catal. 59, 1438-1457 (2016). [2] D.A. Hansgen et al., Nat. Chem. 2, 484-489 (2010). [3] A.K. Hill & L. Torrente-Murciano, Int. J. Hydrog. Energy 39(15), 7646-7654 (2014). [4] F. Carraro et al., J. Mater. Chem. A 5, 20808-20817 (2017).

Fig. 121: a) Co K-edge XANES of CoRe1.6.

b) First derivative of the Co K-edge XANES of

CoRe1.6. Beginning of 5% NH3 treatment (green), end of NH3-decomposition

(yellow) and reduced CoRe1.6 ( )).

c) Co K-edge white line intensity changes during NH3-treatment between

200-400°C (reduced CoRe1.6 ( )).

d) Re-reduction of Co between 400-600°C

at the Co K-edge. e) Area for the Co K-edge

white line intensity in CoRe1.6.

Intermediate phases of CH3NH3PbI3 and their application in X-ray photodetectors

The intermediate phases of the organic-inorganic perovskite crystallisation process and their use in aerosol jet printing (AJP) allows the creation of 3D perovskite structures. Heterostructures based on CH3NH3PbI3 and graphene were successfully manufactured using AJP. X-ray detectors based on such heterostructures demonstrate record-high sensitivity values of 2.2 x 108 µCGy-1cm-2.

Hybrid organometallic halide perovskites have been intensively investigated in recent years as highly efficient light harvesters for various optoelectronic applications. Nevertheless, there are many open questions remaining regarding their crystallisation process [1]. It is well-known that organic-inorganic perovskite properties are highly affected by external factors such as temperature, pressure, humidity, etc. [2-4]. Therefore, it is crucial to understand

the crystallisation process under specific conditions in manufacturing of the devices. Rapid crystallisation of CH3NH3PbI3 (MAPbI3) is of particular interest, as it is one of the most efficient photovoltaic materials and is in demand for integration into electric circuits. Upon the fast solvent evaporation of saturated (DMF)·(MAPbI3) solution, yellow micron-long wires appear and then convert to black MAPbI3 upon further DMF evaporation.

X-ray diffraction (XRD) data were recorded at beamline BM01 during the crystallisation process of the wire-shaped MAPbI3. To this end, (DMF)·(MAPbI3) solution was applied on a glass capillary and XRD data were recorded during evaporation of the solvent. Figure 122 presents the XRD profiles of the structures that the solution undergoes upon crystallisation. This study shows that, from a soft framework of the inorganic species in solution, the mixture of two intermediate phases appears, and presents a possible transformation process for (MA)(DMF)PbI3 into MAPbI3. Such fast anisotropic crystallisation is important for the printing of MAPbI3 for both sensing and emitting light applications.