To improve charge transfer efficiency, non-noble metal Cu anchored in the porphyrin center can realize a new ligand-to-linker metal charge-transfer (LLMCT) process in 2D Ti-based porphyrin MOFs. Experimental results demonstrate that 2D Cu-PTM has the best hydrogen evolution activity (5465.689 μmol g⁻¹ h⁻¹), which is about 27.71 times the value of original 2H-PTM (197.224 μmol g⁻¹ h⁻¹). A series of characterization tests, particularly Auger Cu LMM and ESR, proved that the transient Cu^I/Cu^II center played an important role in the new LLMCT process. In brief, electrons can transfer from excited eosin Y (EY*) to the lowest unoccupied molecular orbital (LUMO) level of porphyrin and then transfer to the transient Cu^I/Cu^II center via a fast conjugated delocalized 18-π electron system of the porphyrin unit, which further accelerates the carrier separation and transfer rate. This work provides simpler and more effective tactics to anchor transition elements in 2D porphyrin MOFs and used non-noble metal ions as low-cost auxiliary catalysts to improve photocatalytic hydrogen evolution performance.

In this work, random forest (RF), support vector machine, k-nearest neighbor and C4.5 decision tree, were used to establish classification models for predicting whether an unknown molecule is an inhibitor of human topoisomerase I (Top1) protein. All these models have achieved satisfactory results, with total prediction accuracies from 89.70% to 97.12%. Through comparative analysis, it can be found that the RF model has the best forecasting effect. The parameters were further optimized to generate the best-performing RF model. At the same time, features selection was implemented to choose properties most relevant to the inhibition of Top1 from 189 molecular descriptors through a special RF procedure. Subsequently, a ligand-based virtual screening was performed from the Maybridge database by the optimal RF model and 596 hits were picked out. Then, 67 molecules with relative probability scores over 0.7 were selected based on the screening results. Next, the 67 molecules above were docked to Top1 using AutoDock Vina. Finally, six top-ranked molecules with binding energies less than −10.0 kcal/mol were screened out and a common backbone, which is entirely different from that of existing Top1 inhibitors reported in the literature, was found.

To improve the charge carrier transport efficiency via reducing the transmission distance, a series of 2D MOF nanosheets with several transition metal clusters as metal nodes are prepared by a simple hydrothermal method for photocatalytic hydrogen production, in which PdTCPP integrates a photosensitive porphyrin with cocatalysts so as to realize fast charge carrier transport. The experimental results show that Co–TCPP(Pd) has the most outstanding hydrogen evolution activity (4.40 mmol g⁻¹ h⁻¹), which could be the reason that the noble metal Pd anchored in the porphyrin center plays a significant role in the electron transfer process, that is, the photogenerated electrons generated by the multivalent Co-oxo cluster excited by illumination are transferred from its own LUMO energy level to the self-photosensitized porphyrin ring through –COO–, and then together transferred to the active site of the precious metal Pd in the porphyrin center to achieve effective hydrogen evolution. The results provide us a feasible strategy to integrate the individual photosensitive porphyrin center with the cocatalysts into sole metalloporphyrins so as to shorten the charge carrier transmission distance for ultimately further improving the photocatalytic performance.

This work provided a novel and reliable idea for preparing the integrated metal-sulfides/2D-MOFs via in situ grown strategy to realize the significant separation and transfer of charge carriers.