Energy security could be jointly maintained through the cooperation of different countries or regions. In this circumstance, there has been a large number of energy-related international investment studies. However, the existing academic literature lacks a systematic scientometric analysis of this research topic, so this paper will fill this gap. Using CiteSpace, VOSviewer, and HisCite, this paper analyzes 1014 articles published in the WoS SSCI Collection from January 1998 to March 2022 on the energy-related international investment. This paper comprehensively analyzes this field from four evolutionary dimensions. In the discipline and mainstream journals dimension, the largest change lies in the fact that more than three different disciplines flow into mathematics, while the journal “Environmental Science and Pollution Research” shows a dramatic growth in relevant publications after 2015. Keyword evolution shows a gradual deepening emphasis from attracting energy-related international investment to systematically analyzing the influencing mechanisms of the international investment-energy-environmental quality nexus. Citation clusters identifies two latest clusters, including institutional quality and renewable energy consumption. Citation paths summarize four major evolutionary paths. The overall evolution trend is based on the FDI-energy-environment nexus, and gradually considers the influence mechanism of different factors on this nexus.

Due to the continuous trade friction between China and the United States, for domestic enterprises in China, the cost of importing foreign technologies is increasing. Thus, the independent research and development (R&D) becomes particularly important for the realization of green technology innovation (GTI). This paper establishes a non-linear mediating effect model based on the data of various regions in China from 2012 to 2018. The main results are shown in the following. Firstly, there is an inverted U-shaped relationship between the intensity of intellectual property protection (IPP) and the level of GTI. Furthermore, the independent R&D investment has a masking effect between them. Secondly, by taking the independent R&D investment as a threshold variable, we prove our findings. Considering that the intensity of IPP is at a high level in most regions of China, the above statements mean that the enterprises need to continuously increase their investment in R&D, in order to further improve the regional ability in GTI. Meanwhile, local governments should also stimulate enterprises' willingness to expand their scale in R&D by issuing incentive policies, such as R&D tax incentives and government subsidies.