Porphyrin nanostructures with well-controlled size, shape and functionality can be used for visible-light photocatalysis. In this work, a graphene@porphyrin nanofibre composite was successfully fabricated via arginine-mediated self-assembly of tetrakis (4-carboxyphenyl) porphyrin (TCPP) on graphene nanoplates (GNPs). The formation and crystallisation of the graphene@porphyrin nanofibre composite was fully characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), fourier transform infrared (FTIR), ultraviolet-visible (UV-vis) and fluorescence spectroscopy. The assembled TCPP nanofibers were 50-200 nm in diameter with length in micrometers long, which were densely and uniformly distributed on the surface of graphene. The GNPs@TCPP nanofibers showed enhanced visible-light photocatalytic activity in comparison with free-standing TCPP nanorods for the degradation of Rhodamine B (RhB) and methyl orange (MO). The possible photodegradation mechanism of these dyes by the GNPs@TCPP nanofiber photocatalyst was proposed.

The excited-state dynamics of two molecular dyads, consisting of zinc (1) and free-base (2) porphyrin connected via a peptide linker to a core-substituted naphthalenediimide (NDI) have been investigated using optical spectroscopy. These dyads exhibit rich photophysics because of the large number of electronic excited states below 3 eV. In the case of 1 in apolar solvents, excitation energy transfer from the vibrationally hot singlet excited porphyrin to the NDI takes place with a 500 fs time constant. Electronic energy ends up in the NDI-localized triplet state, which decays to the ground state on a microsecond timescale. In polar solvents, ground-state recovery is faster by 5 orders of magnitude because of the occurrence of charge separation followed by recombination. On the other hand, excitation energy transfer in 2 takes place in the opposite direction, namely from the NDI to the porphyrin, which then undergoes intersystem crossing to the triplet state, followed by triplet energy transfer back to the NDI. Therefore, four distinct local electronic excited states are consecutively populated after excitation of the NDI unit of 2, with the energy shuttling between the two ends of the dyad.

We synthesised aza‐12‐crown‐4 ether‐substituted naphthalene diimide (NDI‐12‐C‐4) and demonstrated its properties as an fluorescent and colorimetric sensor. The NDI‐12‐C‐4 uses the aza‐12‐crown‐4 moiety to bind Li+ ion selectively over larger monovalent cation such as Cs+, Na+ and K+. The sensor is chemically stable due to the crown‐ether, and the appended NDI fluorophore allows leads to optical changes exclusively for the monovalent Li+ ion. UV–vis absorption, fluorescence, cyclic voltammetry (CV), 1H NMR and naked eye‐detection clearly demonstrate selective, sensitive binding of Li+ ion with a detection limit of 5.0 μM. Importantly, reversible binding of Li+ by NDI‐12‐C‐4 was also observed upon addition of EDTA, after which the sensor could be recovered via simple centrifugation, indicating suitability for use in a biological sensor device.

Carbonyl-bridged triarylamine-based, three-dimensional non-fullerene acceptor (R1); device: ITO/PEDOT:PSS/PTB7: R1 (1: 1.2)/Ca/Al; PCE = 9.33%