Electrochemical hydrogen evolution from water splitting for hydrogen production as a sustainable and environmentally friendly strategy has drawn great attention in recent years. Currently Pt-based materials is the most efficient electrocatalysts toward hydrogen evolution reaction (HER), but the inexpensive cost has limited their widespread applications. Finding an efficient and inexpensive substitute HER catalysts is in need.

Pesticides are crucial part of the farming industry as they can be used to control the insects and weeds for better crop yields. Therefore, the use of pesticides is essential in agricultural and veterinary practices to protect the crops worldwide. However, extensive usage of pesticides would cause toxicity of soils and environmental pollution.

Photocatalytic fuel cell (PFC) has been considered as an alternative strategy due to efficient wastewater treatment and simultaneous energy recovery. However, conventional PFC system is enslaved to the unsatisfactory performance due to the limited surface area of electrodes where the main radical reactions principally occur. To resolve this issue, the radical chain-reaction is introduced into the PFC system with the addition of Fe2+/Fe3+ recycling catalysts.

As people pay more attention to indoor air pollution, feasible gas sensor that operates at room temperature has caught huge interest. Conventional materials applied in home gas sensing include polypyrrole (PPy), polythiophene (PTh), polyaniline (Pani).